(navigation image)
Home American Libraries | Canadian Libraries | Universal Library | Community Texts | Project Gutenberg | Biodiversity Heritage Library | Children's Library | Additional Collections
Search: Advanced Search
Anonymous User (login or join us)
Upload
See other formats

Full text of "Dwellers of the sea and shore"

•;: ;,;,; ^: 



.: ,: ,iM.n 













m 



- 

• 


if qp i 




1 


- ": : i" Hi* ^"'S 



l.i 

1 i iiinin ii 


is 




t 


Xit*» JIL*aJ# 


■—Mhi»w ^pfffl ftfjfljfjjfffffjQpQiiji . ^ 




?BW 


c 


3F 









svssv 



E YOUNG PEOPLE'S 

OF SCIENCE 

w£,E/SLOSSON 



» «»■»«»«» » » » » » 

Please 

handle this volume 

with care. 

The University of Connecticut 
Libraries, Storrs 




3 9153 00144994 



The Young People s Shelf of Science 



Edited by Edwin E. Slosson 



DWELLERS OF 
THE SEA AND SHORE 



THE YOUNG PEOPLE'S SHELF OF SCIENCE 

Edited by Edwin E. Slosson 

Director of Science Service, Washington 

Everyday Mysteries 
By Charles Greeley Abbot, D.Sc. 

Dwellers of the Sea and Shore 
By William Crowder 




C W 

w re 

Rj ... 



re s 






> 
c 

're 

bo 
s 
o 

« 






re re 

c v 
re i- 




DWELLERS OF 
THE SEA AND SHORE 



BY 



WILLIAM CROWDED 






:eS 



te=> 



DRAWINGS AND PHOTOGRAPHS 
BY THE AUTHOR 



"Along the shore of the sounding sea 

Homer. 

"In gulfs enchanted, where the siren sings, 
And coral reefs He bare. 
Where the cold sea-maid» n*e to sun their 
>treaming hair." 

O. W. Holmes 



-m 







s% 



PRINTED IN THE UNITED STATES OF AMERICA 



Copyright, 1923, 
By THE MACMILLAN COMPANY. 



Set up and printed. Published September, 1923. 

/Bk 8/ 



Press of 
J. J. Little & Ives Company- 
New York, U. S. A. 



TO 

MY WIFE 



INTRODUCTION 

The great naturalist Agassiz used to say that a 
student did not know his subject until he could present 
it successfully in four different forms: first as a tech- 
nical monograph, second as a scientific lecture, third 
as a popular lecture, and fourth as a simple child's 
tale. Probably the scientific men of our day would 
Hindi or flunk the fourth of these tests. Yet it is 
possible to put the fundamental fact of any science 
into a form to be comprehended by the juvenile mind 
if one knows the knack and takes the trouble to make 
things plain and interesting. 

And nothing is better worth while, for when the 
attention of a boy or girl is once directed toward the 
wonders of nature, and when once he gets the habit 
of looking for the meaning of what he sees, he has 
gained an aptitude of mind that will last through life 
and bring continuously new ideas and inspiration. 

The new views of science that sometimes seem dif- 
ficult and disconcerting to us elders who have been 
brought up on the old-fashioned theories, are often 
clearer and simpler than the old when they are pre- 
sented directly to the fresh and unbiased minds of the 
younger generation. The modern gasoline motor is 
easier to understand than the older steam engine, and 
it is simpler to think of the electric current as a stream 
of electrons flowing through a wire as water flows 

vii 



viii Introduction 

through a pipe than to think of it as a transmitted 
strain in a hypothetical ether. See how readily the 
youngsters take to the mechanics of the automobile 
and the workings of the radio. 

It is the aim of the Young People's Shelf of 
Science to present modern views of the several 
sciences in a comprehensive and attractive form. 
These books are intended to be read rather than to 
be studied. They are not designed to be tasks, but 
recreations. They do not follow the conventional 
classification of the college, but treat of natural and 
industrial processes from a novel and practical view- 
point. They show that science is not a remote and 
recondite study but a part of everyday life, the unseen 
foundation of all we see and do. 

Edwin E. Slosson. 
Washington, D. C, 
July, 1923. 



CONTENTS 



Part One. The Seashore 



CHAPTER 

I. The Seashore Naturalist 



II. 

III. 

IV. 

V. 

VI. 

VII. 

VIII. 

IX. 



X 

XI. 

XII. 

XIII. 



Social Life in the Salt-Water World 

The Moon Snail 

The Starfish and Its Kindred . 
The Comb Jellies and Others 
Some Friends in Armor .... 
Some Friends in Armor {Continued) 
Marine Groves and Gardens . 
Feathers and Feelers 



PAGE 

I 

15 
3i 
50 
70 

85 
103 
117 
141 



Part Two. The Tide Pool 

Flowerlike Forms and Fantasies .... 163 

Camouflage 184 

Curious Creatures 198 

A "Living Fossil" 220 



XIV. More Friends in Armor 239 

Part Three. The Open Sea 

XV. Beyond the Horizon 257 

XVI. Living Lights That Never Die 275 

XVII. Into the Depths 293 

XVIII. Life in the Ancient Seas 307 

XIX. Our Salt-Water World 318 

Index 331 

ix 



ILLUSTRATIONS 
Coelenterates Frontispiece 



PAGE 



A promising spot for the naturalist 5 

Colony of barnacles living on a rock 8 

Caprella; a small shore crustacean 9 

Strong) locentrotus ; a sea urchin 10 

Ophiocoma ; a brittle star 10 

A whelk shell covered with seaweeds, hydroids and tube- 
building worms (found in a tide pool) 11 

Pentaca ; a sea cucumber 12 

Sea squirt; attached to a fragment of a clam shell (photo- 
graph taken in the water) 13 

Seaweed debris left at the tide marks 22 

Orchestia, the sand flea . 23 

The white anemone 28 

Hole drilled in the shell of a mussel by a moon snail ... 32 

Moon snail (photograph taken in the water) 33 

Moon snail withdrawn in its shell. The dark area in the 
opening of the shell is the operculum, or 4k door," which 

protects the animal from without 34 

Mussel attached to a rock 35 

Radula, or rasping organ of the moon snail (greatly en- 
larged) 38 

Egg case of the moon snail 40 

Eg^s of the moon snail (highly magnified). The individual 
eggs can be seen as the small black bodies contained in the 

larger cells 42 

xi 



xii Illustrations 



PAGE 



Free-swimming larvae of the moon snail (greatly enlarged) . 43 

Littorina; a periwinkle shell 48 

Asterias; the common starfish. This individual is growing a 

new arm in the place of one that was lost 51 

Starfish searching for food (photograph taken on the bot- 
tom of a tide pool) 68 

Bolina; a phosphorescent comb jelly (photograph taken in 

the water) 73 

Pleurobrachia; the comet jelly 75 

Pelagia; a jellyfish 77 

Disk of a dried jellyfish. A transparent film through which 
type easily can be read is all that remains after exposure to 

the sun and air 78 

Strobila of Aurelia 83 

Polynoe; the scale worm 88 

Male hermit crab removed from his shell; showing the soft 

unarmored hind body 91 

Hermit crab in a broken shell. The disintegrating shells they 
sometimes use leave portions of their bodies exposed to the 

attack of enemies 94 

Hermit crabs fighting (photograph taken in the water) . 99 

Courtship of the hermit crab (photograph taken in the water) 105 

Male and female hermit crabs. The female is the smaller 

creature perched on the larger shell of the other . . . 107 

Sargassum; the gulfweed 121 

Lessonia; a laminarian seaweed 121 

Egregia; a laminarian seaweed 122 

Macrocystis; a laminarian seaweed 123 

Enteromorpha; a green seaweed 124 

Ulva; the sea lettuce 126 

Fucus, an olive-green seaweed, growing on a rock . . . 128 

Corallina; a red seaweed which resembles coral .... 133 



Illustrations xiii 



PAGE 



Prickly wort; a flowering plant of the seashore . . . . 138 

Salt wort; a flowering plant of the seashore 139 

Footprints of a herring gull 144 

A staphylinid, or scavenger beetle. This insect lives on the 

decaying matter at the high-tide mark 147 

Robber fly attacking its prey 148 

Larva of the tiger beetle 155 

Cicindela; the tiger beetle 158 

Tube sponge. A non-calcareous sponge 167 

Clava; a colony of tubularian hydroids (enlarged) . . . 179 

Hydractinia; a colony of tubularian hydroids (photograph 
made of the living animals growing on a shell occupied by 

a hermit crab; greatly enlarged) 180 

Rock crab concealing itself in the sand. The animal is in 
the center of the picture. The fore part of its body and 

the ends of its claws are the only portions exposed . . 188 

Lady crab 196 

Loligo ; a squid (photograph taken on the bottom of a tide 

pool) 200 

Eggs of the squid, attached to a clump of red seaweed. Each 
of the cylindrical objects is composed of a group of eggs 

numbering many hundreds 202 

Baby squid; just hatched (greatly enlarged) 203 

Octopus, or devilfish 204 

Cuttlefish 207 

Meckelia; the ribbon worm, with proboscis partly extruded 211 

Eggs of a flatworm laid on the glass side of an aquarium 

(enlarged) 212 

The mason worm 213 

Serpula; a tube-building worm. This creature has built its 

tube on the dead shell of a whelk 214 

Polycirrus; the blood worm 215 



xiv Illustrations 



PAGE 



Nereis, the sand worm, attacking a smaller individual . . 218 

Jaws of the sand worm ^ 219 

An ancient animal of the seashore (trilobite fossil) . . . 222 

Sow bugs 223 

Limulus; the horseshoe crab 226 

Trilobitelike larva of the horseshoe crab 236 

Horseshoe crab molting 237 

Fiddler crabs. The male, who is readily distinguished by his 
large claw, is toward the left of the picture sitting in the 
ovenlike entrance to his burrow. The other individual is 
the female. Pellets of excavated sand can be seen in the 

foreground 241 

Female fiddler crab. The dark mass on her abdomen is a 

brood of eggs and is known as the "sponge" .... 247 

Zoea of the fiddler crab (greatly enlarged) 251 

Greenland whale 260 

Rorqual 263 

Sperm whale . 264 

Man-eating shark 272 

Basking shark 273 

Noctiluca (greatly enlarged) 279 

Globigerina; a protozoan. The shell of this minute animal is 
in the center, and from it radiate stiff spines of lime. En- 
closing the shell is a frothy mass of living substance from 

which extend numerous fine threads 283 

Shells of radiolarians (greatly enlarged) 285 

Gorgonia; a sea fan 289 

Spicules of Gorgonia (greatly enlarged) 290 

Pennatula; a sea pen 291 

The stone lily; a fossil crinoid which lived in an ancient sea 298 

The sea lily; a living crinoid 299 



Illustrations xv 



PAGE 



Ceratius, a fish which inhabits the deep sea 300 

Nematocarcinus, a deep-sea crustacean 303 

Nummulites 308 

Pterichthys; an ancient fish 313 



PART ONE 
THE SEASHORE 



Chapter I 
THE SEASHORE NATURALIST 

An ancient glacier in its northward retreat over our 
continent left in the vicinity of Glen Cove a legacy in 
the form of great masses of stone, gravel, and sand. 
Centuries of wind and rain have done much to change 
the general appearance of the original deposits, and 
they are now resolved into green-clad hills and marshy 
coves. Owing to the loose character of the soil, the 
rains have washed out valleys of considerable size, and 
where these depressions adjoin the waters of Long 
Island Sound they compose the harbors and coves that 
give these shores their characteristic aspect. 

But the wind and the rain have not been the only 
forces to determine the appearance of this region; the 
sea also has been a mighty factor. Many massive 
headlands have been slowly crumbling away under the 
incessant pounding of the waves. And even to-day, the 
comparatively quiet waters of Hempstead Harbor can 
be seen insidiously trying to level the land of the sur- 
rounding shore. 

Near the mouth of the cove rises a high prominence. 
The gentle ebb and flow of the tides have laid it open 
so deeply that it cannot much longer sustain itself in 
the struggle against the sea; but w T ith the debris thus 
removed, the waters are building a barrier across the 

i 



2 Dwellers of the Sea and Shore 

cove; so, while the land is being destroyed in one place, 
it is being formed anew in another. To a greater or 
lesser extent similar changes are constantly taking place 
in the shore lines of every seacoast in the world. If we 
were to travel along either of our long coasts, we 
should find that the sea seems to be wearing the hills 
away more effectively in some places than it does in 
others. This is due to several causes, chief of which 
are the shape of the shore and exposure to the waves. 
But the work of destruction is always going on; like- 
wise, the work of replacement. In some regions, in 
fact, the land is being replaced at a rate for which there 
is not at present any explanation. Many of those great 
stretches of wide, sandy shores bounded by "dunes" 
are cases in point. Where all the material came from 
for those vast quantities of sand, and which is ever in- 
creasing, is one of the ocean's mysteries. 

If we take up a pinch of sand from any beach and 
examine it under a strong glass, it will be found that 
the separate grains are not worn smooth and round, as 
we might have expected, but that they retain to some 
extent their original sharp, angular appearance. This 
is because the grains, as they are washed about, lie 
with their faces toward one another with a film of 
water between them. The film acts as a protection, 
preventing them from actually coming into contact and 
so grinding off each other's angles. Now desert or 
wind-blown sand grains show a quite different charac- 
ter. Their unprotected edges are rounded, and many 
of them are worn so small that they are in reality 
nothing more than fine particles of dust. 

Where new land is forming on a coast, the shore 



The Seashore Naturalist 3 

generally has an upward slope, and the low tide leaves 
a wide expanse exposed to the action of the sun and 
winds. As the sun-dried sand begins to drift here and 
there, some of it is carried up the shore landw T ard and 
remains. These accumulations gradually grow larger 
and become compacted by the rains; and eventually 
plants take root in them, further binding the sand to- 
gether. Such newly made land is extremely marshy, 
and in certain areas vast tracts of it exist close to the 
sea. At every high tide, the water floods these marshes, 
but eventually their channels become choked up with 
the gathering sands and the sea no longer covers them. 
They are soon filled with vegetation, and their level is 
raised and drained; in this way a swampy waste in- 
habited only by fiddler crabs and snails becomes in time, 
perhaps, the site of a thriving village. Thus, the sea 
gives as it takes. 

On rocky coasts at the base of the cliffs will generally 
be found rocks which have fallen from above. They 
are of all sizes, some of them weighing many tons. 
These for the most part have been dislodged from the 
parts of the cliff which are out of reach of the ordinary 
action of the waves; in this case the agency for their 
downfall has been the rain or frost or both. Rain, in 
its descent from the clouds, absorbs certain gases from 
the air which, when combined with water, have a dis- 
solving chemical action on the rock. In time this causes 
the face of the cliff to become pitted and cracked, often 
loosening considerable masses of material. In latitudes 
of frosts this weathering process is hastened by the 
freezing of the water that fills the cracks. The con- 
version of the water into ice is accompanied by an 



4 Dwellers of the Sea and Shore 

expansion, and this acts as a wedge forcibly splitting 
the rock apart. The fractured rock may not at once 
fall, being held in its place by the binding action of the 
solid ice, but when a thaw comes the weakened material 
gives way and is precipitated to the beach with a 
mighty roar. Here the waves take up the work of 
further disintegration; at every storm the rocks are 
rolled around and jostled against each other until they 
are broken into smaller fragments and ground down 
into pebbles and sand. 

No other region offers so pleasing a variety of pic- 
turesque scenes as does the seashore. On the one side 
is the colorful water, incessantly in motion, ever-chang- 
ing in its aspect; on the other, the rugged cliffs or 
maybe quiet coves or bays fringed with a beach of 
glistening sand and backed by hills and fields bedecked 
with verdure. The frequent changes in the character 
of the land further increase the variety of these scenes. 
Where it is composed of soft or loose material we find 
the coast line transformed into graceful curves, and the 
beach is an unbroken stretch of very fine sand; but 
where rocky cliffs exist, the aspect is often wild, and 
the shore is strewn with stones and bowlders of every 
size. And with what delight do we watch the incoming 
waves as they roll over the sand and pebbles or wash 
around the rocks ! 

The picturesque in nature is attractive even to the 
most passive observer, and many who see no beauty 
in small things are constrained to pause with admira- 
tion in the presence of natural spectacles. But the true 
lover of nature will find many other attractions than 
scenic beauty to allure him to the shore. He loves to 



The Seashore Naturalist 5 

read the history of the sands and rocks, to observe in 
what way the general scenery of the coast is deter- 
mined by the character of the land, and to discover 
from the beach what has been the action of the waves 
in shaping the contours of the cliffs. He finds a unique 
pleasure in observing which plants are peculiar to the 




A PRO\II>IN<; SPOl H>k I HE NATI'RAI.IST. 



shore, and how they differ from the flowering forms 
away from the sea. He also finds a delight in watching 
the sea birds, the insects, and other lower forms of 
life, and in learning how these various creatures are 
distinguished by structure and habits from those of 
inland regions. 

Nor is he ever at a loss for opportunities to follow 



6 Dwellers of the Sea and Shore 

his favorite pursuits. Regardless of whether the tide 
be high or low, or whether his locality is one of sand 
or rocks, or even mud, an endless variety of forms 
await his inquiring notice. 

To the beginner — and to the experienced naturalist, 
too — the character of the shore is important, as it in- 
dicates to a large extent the types of plants and animals 
which are most likely to prevail. A sandy shore, al- 
though appearing quite barren and uninteresting to the 
ordinary observer, nevertheless teems with life. But 
its inhabitants live mostly under the surface where their 
presence often can be detected by the openings to their 
burrows. Some of the burrowers, such as certain 
clams, betray themselves by sending conspicuous jets 
of water into the air. However, the greater part of 
the underground population gives no visible sign of 
existence; and to one who was unaware of the fact, it 
would seem incredible that a turn of the spade will 
reveal a numerous crowd, among which will ofttimes 
be found some of the most beautiful creatures in the 
animal kingdom. Snails, crustaceans, and worms are 
extremely abundant over the entire beach, and careful 
scrutiny of drifted sea wrack will detect a host of other 
forms. In the water, of course, the evidence of life is 
more obvious. When the tide comes creeping upward, 
a numerous group begins to assemble. Almost at the 
very edge of the water, nosing their way here and 
there, can be seen the minnows. Some of the tribe 
peculiar to our eastern coast will show a delightful 
familiarity by nibbling harmlessly at the wader's toes or 
ankles. These are the Mummichogs ; and in brackish- 
water regions they outnumber all other shore fishes. 



The Seashore Naturalist 7 

In a manner of speaking, many of the fishes may be 
quite visible but yet unseen. This is because of their 
shape or coloring, which makes them inconspicuous 
against the bottom. Unless one had an unusually keen 
eye for such things, it would be difficult to distinguish 
some forms from inanimate objects. The slender pipe- 
fish, for instance, resembles the stemlike fragments of 
vegetation washed back and forth by tidal currents. 
Visible forms are plentiful, nevertheless; among these 
are the sea robin, that strange fish which crawls as well 
as swims; the skate, an innocuous cousin of the shark, 
and the shining silverside. Then perhaps on rarer oc- 
casions one may obtain a glimpse of that quaintest of 
creatures, Hippocampus, the little sea horse. Crus- 
taceans, too, are common. Hermit crabs can be seen 
carrying on their interminable brawls, sand crabs are 
present, half buried and awaiting their prey, while 
shoals of shrimps frequently go flashing by. 

As I have hinted, muddy shores are not without 
their interest. These are usually associated with 
marshy regions of brackish water or with shallow bays 
and estuaries. Burrowing in the muddy banks will be 
found the fiddler crab, a grotesque creature with a 
claw almost as large as the rest of his body. 
In the groves of eelgrass, which are submerged at 
every tide, many small animals are living which are 
seldom seen elsewhere. The eelgrass is a flowering 
plant and is one of the very few which will grow in 
salt water. Among the animals which crawl over its 
bladelike leaves is a little snail which attaches its egg 
cases to the plant, and these look so like the seeds that 
are formed in the grooves of the leaves that they cannot 



8 Dwellers of the Sea and Shore 

easily be told apart. Other creatures have a body 
resemblance to the shape and color of the leaves. At 
the roots, in the mud, other small animals are abun- 
dant. The pools and channels of mud flats contain 
numerous varieties of mud crabs; if one is discerning 
he will often be able to find in such places sluggish 
types like the spider crab, which hides under decaying 
weeds or covers itself with vegetation, and the mud 




COLON' Y OF BARNACLES LIVING ON A ROCK. 

crab, with a load of silt and debris tangled with the 
bristles on its back. Beauty is also present. Attached 
to the submerged plants are silky sprays of the wonder- 
ful hydroids, but a good glass is required to reveal the 
delicate and exquisite structure of their plantlike bodies. 
Indeed, there is no end to the charming revelations one 
can make with a glass, and this holds equally true for 
the waters of every character of shore. 

Rocky shores w 7 ith their clefts and crannies and 



The Seashore Naturalist 9 

numerous pools also have an interest all their own. 
The seaweeds which grow in great abundance and 
variety harbor in their fronds many animal forms 
which do not occur in localities of sand or mud. In 
the struggle for existence among both the plants and 
the animals which inhabit the shores every possible 
advantage is sought by the individuals. This is par- 
ticularly plain among the rocks. Every bowlder bears 
on its seaward side a colony of barnacles, and vigor- 
ously disputing the space these creatures occupy are 




CAI'kLLLA, A SMALL iiloRL CKUS1 



mussels and other stationary mollusks. Even the sea- 
weeds contest the right of the barnacles to dominate; 
they grow so thickly in some places that the latter are 
often crowded out. These rockweeds in turn support 
a curious population. Crawling over the leathery 
fronds or firmly fixed thereon are sea spiders, moss ani- 
mals, snaillike worms which secrete spiral shells, and 
in sundry places may be seen attached by its hind legs, 
swaying its lengthened body to and fro, that oddest of 
crustaceans, little Caprella. Among the other crea- 
tures to be found on the fronds are certain snails, which 
simulate the color of the plant, or are striped to make 
closer their resemblance. 

When the tide is out there will be found secreted 
under ledges and in sheltered places starfishes and sea 



10 



Dwellers of the Sea and Shore 



urchins and different sorts of crustaceans who are 
active only when submerged. But the less exposed 
nooks shelter permanent residents as well. In these 




STRONGYLOCENTROTUS: A SEA URCHIN. 




ophiocoma; A BRITTLE STAR. 



places live many delicate seaweeds which are unable to 
endure the force of the waves or the withering action 
of the sun; animals, too, no less inclined to brave the 
open, thrive in these little solitudes in considerable 
numbers. Below the low-tide mark, pink, orange, or 
scarlet incrustations of small sponges may be seen like 



The Seashore Naturalist 



ii 



luminous patches of color in the gloom of miniature 
grottoes; while partly masked by the long pale-green 
threads of vegetation are numerous creatures in hiding; 
some are waiting to pounce upon their prey and others 
are seeking seclusion from their enemies. 

The numerous pools that occur on every type of 




A WHELK S SHELL COVERED WITH SEAWEEDS, HYDROIDS AND TUBE-BUILDING WORMS. 

FOUND IN A TIDE POOL. 



shore afford a refuge for some species of plants and 
animals which ordinarily are found only below the tide 
marks. In the clear, peaceful waters are usually con- 
tained the corallines, tufts of pretty pink and white sea- 
weeds w T hich look like miniature branches of coral, and 
the brittle stars, slender, active starfishes which climb 
about the sea plants, and the attractive sea anemones, 
variously colored creatures of prey which resemble 



12 Dwellers of the Sea and Shore 

flowers. On the pebbles or sand that forms the floor 
of the pool itself, may appear the transparent, phan- 
tomlike prawn, gently waving its long filamentous 
feelers, then darting suddenly backward so swiftly that 
the eye cannot follow the movement; or, it may be, 
that a chance view may be caught of the scallop, that 
ornamental clamlike creature which swims by snapping 
together the valves of its shell. 

It so happens that on the piles of wharves many 
kinds of sea creatures will find a lodging place. Some 




pentaca; a sea cucumber. 



of these are attached forms such as hydroids, anem- 
ones, moss animals, and sea squirts; others, like the 
shipworm and the gribble, are boring animals, and are 
therefore less conspicuous. 

Thus, there is much to find and admire among the 
living forms which inhabit the seashore. It is perhaps 
the most interesting of all the haunts of life. Although 
certain types may occur invariably in those regions that 
favor their development, life on the whole may in dif- 



The Seashore Naturalist 13 

ferent localities be surprisingly varied and even in one 
place be very diverse. In fact, it changes from week to 
week. Repeated visits throughout the year seldom fail 
to mark the presence of numerous hitherto absent 
forms. The finding of these forms, the discovery of 
their marvelous beauties, the learning of their ways, 
afford the lover of lower living things many delightful 
and fascinating hours. 




sea squirt; attached to a fragment of a clam shell. '.PHOTOGRAPH taken 

IN THE WATER.) 

Harbor Beach and its environs is one of those 
regions that in a degree comprise within a small com- 
pass the several kinds of shore formation and the vari- 
ous inhabitants which have just been reviewed. 

Here, the sheltered cove, the salty meadows, the 
bowlders, the sandy reach, the nodding shore plants and 
flights of sea birds represent to the stranger nothing 
more, perhaps, than a quiet place in a peaceful coun- 
try; yet it is the realm of great mysteries, the 



14 Dwellers of the Sea and Shore 

scene of thrilling adventures, the gateway to a 
strange world. 

We all like to adventure. And who does not love a 
mystery? It whets our curiosity and adds zest to our 
lives. Surely, this would be a dull life if there was 
nothing to learn, nothing to excite our imagination or 
our wonder. Therefore, to resolve some of these mys- 
teries, to recount an occasional adventure, and to follow 
a few of the paths leading throughout this amazing 
realm, shall be the purpose of the ensuing chapters. 



Chapter II 
SOCIAL LIFE IN THE SALT-WATER WORLD 

Who has ever visited the seashore during a storm 
without a feeling of great awe as the thundering waves 
broke against the rocks or hurled themselves with 
their foaming crests high upon the beach? With each 
succeeding surge of the mighty masses of water the 
impact causes the very earth to tremble. If one is 
of a reflective nature, those truly are tremendous 
moments. It is then that one is impressed with the 
significance of the warfare which is being waged by the 
sea upon the land. 

Although one can well understand how the most 
obdurate of coasts sooner or later must give way to the 
incessant pounding, how is it that the continents of the 
world have so long sustained themselves in the strife? 
Does it not seem that ultimately dry land would com- 
pletely disappear? 

Well, it is true that shore lines are breaking down. 
Indeed, it is quite certain that considerable bodies of 
land have dwindled away for this very reason. But it 
is equally true that notwithstanding the frittering away 
of its coasts a continent occasionally actually increases 
in size. 

This apparent paradox is easily explained. The 
earth, as we all know, was once very hot; it is at 

15 



1 6 Dwellers of the Sea and Shore 

present a cooling mass. Now a cooling body contracts, 
and as it does so it has a tendency to warp. Particu- 
larly does this become evident in the case of our globe. 
Although its rock-ribbed surface is seemingly solid, 
nevertheless, it is endowed with great plasticity, and 
consequently the shrinking shell results in rumpled 
ridges and rugosities. Time and the elements have 
done much in the past to obliterate these folds and 
wrinkles, but they are still manifest in what is left of 
the mountain ranges and in the abyssal valleys of 
the sea. 

In many regions in the world the contracting crust 
is causing certain portions of continents slowly to rise 
while at the same time, but in another place, it is 
causing the land to lower. In the latter event the sea 
hastens the disappearance. Where an elevation is 
taking place, however, it sometimes progresses more 
rapidly than the waves can work. Notwithstanding, 
to some extent the sea is always cutting away our 
shores. 

There is enough water in the sea easily to cover the 
entire earth, provided the earth were a perfectly 
smooth sphere — that is, if all the mountains and valleys 
of the land and sea were brought to a common level. 
But that the earth was ever completely inundated at 
one time seems unlikely, for it appears that the more 
solid part has always been too unstable. Now a por- 
tion is up, then it is down. This seesawing, this oscil- 
lating of the land, has continued throughout so many 
ages and in so many places that to-day there is no con- 
tinent or part of a continent which has not at some time 
been at the bottom of the ocean. What is more, it is 



Social Life in the Salt-Water If'orld 17 

very probable that some parts of the ocean floor form 
the site of what in some previous age were wind- 
swept peaks or sun-kissed plains. Of our continents, 
then, the ocean is, in truth, at once the cradle and 
the grave. 

It is plain that the mobility of the sea is no incon- 
siderable factor in shaping the destiny of the land. 
This mobility, however, is manifested in another way, 
and in one which is very vitally concerned with the 
destiny of all life peculiar to the seashore. I here refer 
to the phenomenon of the tides. 

Most of us know vaguely, perhaps, that the tides are 
in some way influenced by the moon. This, in fact, 
becomes evident to the most casual observer. For the 
slightest acquaintance with the seashore soon reveals 
the singularity that at the periods of new moon and 
full moon occur the greatest variations in the rise and 
fall of the water. In other words, at the time of these 
two phases of the moon, which is to say, every fort- 
night, the tides reach their highest point during the 
flood and their lowest mark at the ebb. Thencefor- 
ward until two weeks later, when the moon is in the 
quarter phase, the variations daily grow less; after this 
they gradually increase again until the time of new or 
full moon. Now, if one is more than ordinarily ob- 
servant he will have noticed further that the time of 
high tide at any selected spot is always the same for 
any given period of the cycle of the moon. 

It will be inferred, therefore, that the tides move 
in some mysterious manner in response to the attraction 
of a magnetic moon. But here is a curious thing. We 
know that the sun has a far greater attractive influence 



1 8 Dwellers of the Sea and Shore 

on the earth and its oceans than has the moon. What 
is it, then, that gives the latter its apparent precedence 
over the sun in the regulation of the tides? 

To conceive this clearly, we must take into account 
the relative distances of these two bodies from the 
earth. Our globe is about eight thousand miles in 
diameter. Yet this is a very small fraction of the dis- 
tance to the sun which, roughly speaking, is ninety- 
three million miles away. Consequently the pull on the 
earth is about the same throughout its entire mass; or, 
to put it another way, the attraction for that side of the 
earth nearest the sun is but slightly more than for the 
side more remote. A quite different aspect presents 
itself, however, when we consider the moon. The dis- 
tance of our satellite from the earth being only a quar- 
ter of a million miles, it will be seen that the diameter 
of the earth at once becomes a very considerable frac- 
tion. The result is that the side of the earth facing the 
moon is subjected to a much stronger pull than the op- 
posite side. Now the waters of the ocean respond 
more readily to the attraction of the moon than does 
the hard crust of the earth, and as a consequence they 
are caused to bulge out on that side nearest the moon. 
Again, since the attractive force of the moon is weakest 
of all at the opposite side, and since the waters on that 
side are attracted less than the solid earth — the latter 
being pulled away, so to speak — they bulge outward on 
the side away from the moon also. 

From this it will be seen that we get a condition 
wherein two high tides are produced simultaneously 
on opposite sides of the earth. It must be borne in 
mind, however, that the earth is continually turning on 



Social Life in the Salt-Water World 19 

its axis, a complete rotation occurring every twenty- 
four hours; and as the tides necessarily follow the 
moon which in itself revolves around the earth approxi- 
mately every twenty-eight days the changes in the tides 
occupy on the average six hours and a quarter each; 
thus making high and low tides occur about an hour 
later every day. 

Now in all strictness the influence of the sun is not so 
negligible a factor as it may appear from the fore- 
going. Although its attraction is considerably less than 
that of the moon, it is still an attraction. This we 
find is evident in the fortnightly fluctuations of the 
tides. As was pointed out, extreme high and low tides 
are at the time of the new and the full moon, whereas 
the least variation is during the quarter phases. The 
former are known as u spring tides" ; the latter as 
u neap tides. " As we follow the moon in its various 
phases, we find in starting with the new moon that it 
is nearly on a straight line — sometimes exactly so — 
between the earth and the sun; therefore, the attrac- 
tion of the sun added to that of the moon, assists the 
latter, as it were, in its pull, thus causing a spring tide. 
About a week later when the moon is in its first quarter 
it is in a position at right angles from the sun as viewed 
from the earth. The tides are now more modified, for 
the moon no longer has the help of the sun. The truth 
is, each of these bodies is trying to produce a tide all 
its own, the moon on one meridian and the sun on 
another, but a quarter of the way around the earth; 
the consequence is that though the moon's pull is 
stronger its efforts are minimized by the sun's power 
in holding the water in check. A neap tide is the result. 



20 Dwellers of the Sea and Shore 

In another week we find the moon full and in a line 
opposite from the earth to the sun. Although pulling 
in opposite directions they produce a harmonious re- 
sult. For as two tides are formed at the same time, 
one on each side of the earth, it follows that the in- 
fluence which is one body's loss is the other's gain. The 
following, or third, week we see the moon in its last 
quarter; it has by then completed three-fourths of its 
cycle. Once again the moon is at right angles from the 
sun; once again the tides are at their slightest range; 
from this time onward they will increase daily until the 
moon is full, the cycle then continuing as before. 

If the earth were entirely covered with water, the 
tidal swell would travel in a westerly direction and 
keep its place regularly on the meridian of the moon; 
but we know that actually the movements of the waves 
are exceedingly complex. Observations along different 
points of our seaboard show that there is sometimes a 
great difference in the time of high tide between two 
or more places situated close together. For example, 
high water does not occur in Hempstead Harbor until 
more than three hours after the time of high tide at 
Governor's Island in New York Harbor, less than 
thirty miles to the west. Now this lagging of the tides 
is noticeable to a great extent on all continental shores, 
and it is due partly to the retarding action of the latter, 
partly to the inertia of the water itself, but mainly to 
the irregular distribution of the land which breaks up 
the tidal wave into innumerable wave crests, vastly 
restraining their progress. 

Let us note one more singularity. This is the dif- 
ference in range, or vertical movements of the tide, in 



Social Life in the Salt-Water World 21 

different parts of the world. It is well known that the 
differences between the tide levels of continental seas 
are greater than those to be observed on the shores of 
oceanic islands. Now this is also due to the irregular 
distribution of the land which has a tendency to deflect 
the wave crests, causing them to pile higher than they 
would do in the open sea. But it so happens that dif- 
ferences occur on the same coast line. High tides are 
especially noticeable where they break into gradually 
narrowing estuaries and other channels; the incoming 
water, being compressed laterally, is consequently in- 
creased in height. Thus, in Hempstead Harbor, which 
receives the retarded waters of the Sound, the mean 
variation of the tides is about six feet, but in the Bay 
of Fundy where the incoming tide piles up with great 
force, it is said the water reaches the extreme height 
of ninety feet. 

Now, I have gone into this matter of the tides at 
some length not alone because of its interest to those 
making their first acquaintance with the sea, but also in 
order better to visualize for the reader the funda- 
mental nature of an element that has largely to do with 
the interpretations we shall make of the strange habits 
prevailing among many dwellers of the shore. 

Undoubtedly, the greatest attraction of the sea- 
shore for the collector and naturalist is at the time 
of the ebbing of a spring tide. As the retreating 
waters lay bare the land, a promiscuous multitude 
makes its appearance. From all directions come crea- 
tures of every description. Through the air, from out 
of the earth, and over the land they arrive : birds, in- 
sects, and crustaceans. Mollusks, too, and worms and 



22 



Dwellers of the Sea and Shore 



beasts with spines claim our attention as the tide leaves 
these animals high and dry or stranded in some shallow 
pool. The tidal zone is peculiar in that, while its upper 
limit marks the frontier between two worlds whose 
denizens are totally unlike in habits, the region between 
this and the lowest limit of the spring tides is one that 




SEAWEED DEBRIS LEFT AT THE TIDE MARKS. 

has an alternating condition which makes it periodically 
favorable to land or marine animals. In brief, the 
tidal area is a sort of u no man's land" alternately 
occupied by the animals of the land and those of the 
sea. It so happens, though, that some can hold their 
ground under either condition, whether this be marine 
or terrestrial. 



Social Life in the Salt-Water World 23 

As the tide turns from high to low it leaves one un- 
mistakable mark to indicate its highest level. This is 
in the form of a long line of wilting seaweed and or- 
ganic debris. Of this low-lying heap, by far the greater 
portion consists of the common green seaweed, Ulva, 
or sea lettuce, as it is popularly called. The sea lettuce, 
having become detached from its anchorage on the 
bottom, is carried ashore by wave action. Clumps of 
olivegreen and brown seaweeds sometimes are in the 
mass, and often one will find those rarer and more 



orchestia; the sand flea. 



delicate forms, the brilliant red plants of the deeper 
waters. Particularly are the latter in evidence after 
a period of stormy weather. Often, too, a sponge is 
torn from the outlying bottom and drifts about, finding 
its way at last to the tangled tide mark on the shore. 
As far as one can see, this telltale line extends itself 
along the beach. At first sight it would appear that the 
moist mass is destined shortly to become a heap of 
rotting refuse. It is not, however, so destined. Barely 
does it become stranded by the tide when it is beset by 
a swarming population. Flies, beetles, and other in- 
sects are engaged in its reduction. But the most active 



24 Dwellers of the Sea and Shore 

and efficient agent is one that is properly from the sea- 
shore itself. This is the sand flea, Orchestia. This 
busy little scavenger is the purifier of our shores. With- 
out him our beaches would tend to become places to be 
avoided rather than regions of charm. His number is 
legion; yet he works virtually unseen. If, however, we 
turn over the debris about us we will find a surprise ; 
the ground underneath becomes alive with him. Our 
intrusion on his privacy, however, causes a multitu- 
dinous dispersal, for he immediately scampers away in 
hundreds and buries himself in the sand or finds some 
other hiding place. 

No sooner does the receding tide expose a portion 
of the beach than it takes on an animated aspect. 
From a thatch-covered mud bank near at hand, fiddler 
crabs emerge in droves. Like herds of grazing cattle, 
they follow the creeping water and search among the 
stones and pebbles for the minute plant food on which 
they live. The males are easily distinguished by the 
enormous claw each individual carries. No other crab 
but the fiddler is provided with a pincer of such prodi- 
gious proportions. 

A bird alights on the shore, and a panic ensues. 
Pell-mell the fiddler crabs rush toward the thatch grass 
and plunge indiscriminately into the burrows which 
honeycomb the bank. Fear inspires them to make no 
choice. It is every crab for itself. In the alarm each 
dives sidewise into the most convenient retreat, and it 
sometimes happens that a single burrow is completely 
filled with the fugitives. 

We recognize the newcomer as the green heron; it 
is hunting for a meal. It settles down on the sand and 



Social Life in the Salt-Water World 25 

stands motionless near the edge of the water. The 
fiddler crabs, in common with the majority of wild 
creatures, recognize only moving objects, and it is not 
long before they once more emerge from their hiding 
places and wander toward the water. 

But see what is happening around the bird. Rising 
out of the smooth sand other fiddler crabs can be seen 
stealthily and warily making their appearance. Unless 
you are in the secret you would think that these are 
members of the mud-bank colony which had, of neces- 
sity, taken refuge in the sand. But they are, in fact, 
entirely different individuals. This region abounds 
with two species of fiddler crabs whose habits are com- 
pletely dissimilar. One ( Uc a pugilator) , that which 
first engaged our attention, lives only in the muddy soil 
peculiar to the thatch-grass meadows. It is of a dark 
slaty gray — somewhat like the soil in which it lives — 
except in the case of the male whose great claw, oft- 
times much larger than the rest of the body, is of a 
bright yellow hue. The other species (Uca minax) 
makes its home in the sand, where each crab occupies 
a burrow of only a few inches in depth. This fiddler 
crab is nearly alike in shape with the mud dweller. 
But in color, as well as in its general habits, it is far 
more attractive than its brethren of the muddy banks. 
However, as a later chapter will be devoted to this 
interesting animal, we need not further consider it 
here. Let it suffice by saying that it is this species 
which we find making its appearance near the motion- 
less heron. 

Suddenly the bird plunges its long beak into the 
water, pulls out a coiling sandworm, and with a short 



26 Dwellers of the Sea and Shore 

run takes the air with lazily flapping wings. Another 
panic; another rout in which all fiddlers of both species 
take part; then, once more, not a crab is in sight. 
Plainly, the fiddler crab is a shy creature. Notwith- 
standing that these animals live together by the thou- 
sands, and that they are of a conspicuous size (the 
adults are more than two inches in breadth) their ex- 
treme timidity makes them little known to the average 
seaside rambler. The appearance of any stranger in 
the neighborhood, whether it be bird, beast, or man, 
is always the signal for their retreat. Still, one can 
make the fiddler crabs' acquaintance if he but has the 
patience to wait quietly near their burrows. And I 
may add that by so doing he will be amply rewarded 
for his pains. 

By the time the ebbing tide is three hours old — that 
is to say, when it is about halfway out — numerous 
rocks studded with barnacles have already been left 
high, if not quite dry. Nearly all of these irregular- 
shaped bowlders have concealed in their depressions 
and crevices clusters of starfishes. Here and there the 
uneven ground has retained the water, and in these 
transparent pools one catches a glint of gleaming sun- 
light from the iridescent dead seashells strewn over 
the bottom. Broad bright areas of rippled scurf sand 
also have made an appearance, vying with the brilliance 
of a summer sky in their lovely whiteness. 

But the beauty of inanimate nature is not the only 
beauty that the lowering tide reveals. Many animals 
adorn the glistening beach. Wherever one may search, 
in the tide pools, under the stones or in the sand, he is 
sure to encounter creatures whose sightliness is seldom 



Social Life in the Salt-Water World 27 

matched by the dwellers of dry land. Now, strange to 
say, among the most beautiful are many of the worms. 
Look at Nereis, the sea worm. This animal usually 
lives under stones and in the sand, but ofttimes fre- 
quents the tide pools in search of prey. Seen in the 
latter it is like a glittering chain of blue-green opals 
flanked with precious coral. The sides of its colorful 
body are lined with gills of pearly pink; from under 
every gill projects a sheaf of bristles reflecting the 
luster of pure gold. But the palm of beauty unques- 
tionably should be awarded to Aphrodite, the sea 
mouse, a worm whose appearance has excited the ad- 
miration of every age. To the untrained eye it does 
not look like a worm; and therein, perhaps, lies the 
secret of its charm. This, in a way, is unfortunate. 
Had earlier observers known its identity, it is probable 
that ere now many other members of the group would 
have shone in popularity by reflected light; conse- 
quently, their habits would be better known. Its everv 
motion is productive of a play of prismatic tints, but 
it is vain to attempt an adequate description of the in- 
effable nuances, the evanescent hues, that endow Aphro- 
dite with its strange beauty. Graphic representation 
itself is unable to reproduce the charming colors caused 
by the diffraction of light on the translucent texture of 
its hairy covering. 

It must be admitted, however, that beauty in some 
instances is merely a mask. It often hides an unlovely 
trait. What could be more enchanting than the white 
anemone (Sagartia leucolena) as it stands no taller 
than one's thumb, with its translucent tendrillike arms 
undulating in the soft currents of a tide pool? Incom- 



28 



Dwellers of the Sea and Shore 



parably gracile, it sways innocently, innocuously, the 
verisimilitude of an alluring spectral flower. Yet one 
would little suspect its lethal nature. But should a 
young sea worm or other small wanderer chance to 
glide against the ghostly petals, it is lost. For the 
petals are murderous tentacles; and they can inflict a 




THE WHITE ANEMONE. 



paralyzing shock, overwhelming the luckless victim like 
the surge of a hundred thousand volts. 

Let us attend to the tide. When the water has 
reached its lowest ebb it has at the same time reached 
the point of its greatest productivity for the collector 
or observer. Yet for that matter, in the five hours and 
more which have elapsed during the tidal descent, 
enough material will have been found to satisfy the 
most ardent hunter. It is at low spring tide that all 



Social Life in the Salt-Water World 29 

manner of animals are to be found; for the tidal region 
between the low-water neaps and the low-water springs 
is inhabited by a far more numerous species than any 
other part of the seashore. All sorts of fishes, crus- 
taceans, mollusks, worms, etc., will be found in hiding 
here waiting to be covered by the next tide. For the 
most part these will be found beneath the stones, in the 
ground, and, in the case of anemones and certain other 
low forms, attached to the under surfaces of the stones 
themselves. Living seaweeds are also in abundance, 
and in their wet fronds are sheltered minute creatures 
whose strange form and structure are to be revealed 
only by the microscope. 

There is, furthermore, a conspicuous abundance of 
the larger animals of the shore. Limulus, the horse- 
shoe crab, can be seen plowing his way through the 
mud. Around about the molelike creature the soft 
ground is pitted with innumerable holes of about the 
diameter of an earthworm's burrow. Geyserlike jets 
of water ejected from various orifices indicate the 
presence of the soft-shelled clam {My a arenarea) . 
Periwinkles and other snails are here, there, and every- 
where crawling over the surface of the mud, leaving in 
their trails their familiar furrow r s. Cancer, too — the 
rock crab, so miscalled — we will see; half buried, but 
on the alert, it awaits with its dangerous-looking, bone- 
crushing forceps in readiness to pounce upon some 
smaller passer-by. 

To enlarge upon the wealth of living forms found 
here would be wearisome. Yet the most casual ref- 
erence would be incomplete without mention of the 
mussels. The extensive black beds of these mollusks 



30 Dwellers of the Sea and Shore 

are exposed at every low spring tide. So great is the 
number of the individual units that they are to be esti- 
mated only in millions. Excepting, perhaps, the bar- 
nacles, they are the commonest animals in this region. 

Now, although the mussels are peaceable creatures, 
their life is not exactly a peaceful one. Living as they 
do on the organic motes held in suspension in the water 
and on live food of microscopic dimensions, they have 
no need of weapons of offense; and as to defense, the 
two-valved shells which protect their soft bodies are 
inadequate to resist the attack of their enemies. And 
these are many. Few flesh eaters there are that do not 
take toll of their numbers. Incapable of locomotion — 
as that term is ordinarily understood — the mussels are 
easy prey to the starfish, sea urchin, and other slow- 
moving animals; and these, together with crabs, fishes, 
and birds, are continually engaged in their slaughter. 

Indeed, it would sometimes appear that the mussels 
are bent upon destroying each other. They exist in 
such enormous numbers, layer on layer, that they fre- 
quently actually poison one another by their waste 
products. Many, moreover, are smothered by the ac- 
cumulation of silt and other matter settling down from 
the upper masses. 

Nevertheless, their worst foe is not themselves. 
Their deadliest enemy is, however, not far removed in 
kind. It is, in short, another mollusk. This mollusk is 
the moon snail, a creature which is an outstanding 
example of the amazing contrasts sometimes found in 
this strange world. 



Chapter III 
THE MOON SNAIL 

About the first thing to strike the attention of the 
amateur naturalist on his initial acquaintance with the 
sea is the countless number of dead shells that whiten 
the beach at various places along the shore. Cast up 
by the incessant action of the winds and waves, these 
objects of sundry shapes and sizes are imbedded in the 
sand and frequently are heaped in veritable windrows. 
Indeed, the very sand that beautifies the beach is not 
wholly of true sand, but to a large extent is composed 
of the crumbling fragments of this selfsame shell ma- 
terial. Everywhere in sight, littering the shore, is 
monumental testimony of the millions of mollusks con- 
stantly meeting their death in the adjacent waters. It 
is as if some giant hand had swept the sea and left the 
shells to bleach in the blighting light of the seasonal 
suns. 

Often the patterns of these fragile tenements are 
varied and pretty. And there are some of exquisite 
hues. But by far the greater part of these enormous 
ossuaries consists of the remains of those homeliest of 
mollusks, the mussels. 

Now few animals of the sea die directly from old 
age. Their existence is generally terminated by attacks 

31 



32 Dwellers of the Sea and Shore 

from natural enemies or other accidents. These ene- 
mies are sometimes large, sometimes small; they may 
be microscopic. Surprising as it may appear, after 
long resistance to the former, many animals reach a 
ripe old age only to succumb to the insidious attacks of 
the latter. Of course, the weaknesses due to old age 
make them especially liable to the invasions of these 
invisible hordes; nevertheless, sooner or later, the great 
majority of marine animals meet a premature death. 
Thus it has been with the occupants of the shells on 




HOLE DRILLED IN THE SHELL OF A MUSSEL BY A MOON SNAIL, 

the beach. In the case of the many, both the bivalves 
and the univalves show one unmistakable clue to the 
identity of the assassin who dispatched them. This is 
a small round perforation in the shell through which a 
wheat straw can be passed. It is the mark of the moon 
snail or one of its carnivorous brethren. 

The moon snail (Lunatia heros) is easily the largest 
shell-bearing mollusk in these waters. When full grown 
its rounded, whitish, spirally coiled shell is about four 
inches long. But like the familiar pond snail, the ani- 
mal crawls on a large fleshy foot. This foot with its 



The Moon Snail 



33 



adhering mantle is of enormous proportions. So large, 
when protruded, as to envelop completely the house 
which was designed to shelter it. Indeed, to see this 
creature retract its fleshy body is to witness a very 
amazing feat. It is like that trick of the conjurer 




MOON SNAIL. (PHOTOGRAPH TAKEN IN THE WATER.) 



where he makes an almost incredible quantity of para- 
phernalia disappear into his cornucopia. 

The moon snail travels in search of its food either 
under or over the surface of the sandy bottom. And 
for a snail it moves with striking rapidity. The pro- 
verbial slowness of the land snail is not reflected in the 
actions of its marine relative. Although in these 
waters it is the greatest enemy of the mussel, it is an 



34 



Dwellers of the Sea and Shore 



eater of all flesh, be this dead or alive. What is more, 
it will with equal readiness devour one of its own 
species. 




MOON SNAIL WITHDRAWN IN ITS SHELL. THE DARK AREA IN THE OPENING OP THE 
SHELL IS THE OPERCULUM, OR "DOOR," WHICH PROTECTS THE ANIMAL FROM 
WITHOUT. 



Curiously, this active creature is blind. Yet it is 
unerring in the detection of its prey. This ability to 
find its food, of course, is due to a sense organ, the 
nature of which is not hard to guess. It is an ability 
somewhat like that of a dog's on the scent of game; 



The Moon Snail 



35 



but with this difference : the dog is guided by the sense 
of smell; whereas the moon snail, from the very nature 
of its surrounding element, is perforce restricted to the 
sense of taste. In short, the effluvium of its food is 
carried in the currents of the water, and this latter 
medium is tasted rather than smelled. 




MUSSEL ATTACHED TO A ROCK. 



In turning to the common prey of the moon snail we 
find that this bivalve differs as greatly in its habits as 
in its appearance. It is possessed of two shells, or 
valves, equal in shape and size. These shells are 
hinged, and when viewed from the side are slightly tri- 
angular, are rounded, and are about twice as long as 
they are wide. Sometimes they attain to a length of 
five or more inches, but more commonly they are three 
inches long. In the living animal they are dark, almost 
black, but exposure soon turns them to a pearl gray. 
Now the mussel is usually content to remain rooted to 
one spot the greater part of its life, which it does by 
attaching itself, when young, to any solid object by 
means of numerous tough silken threads, called byssii. 



36 Dwellers of the Sea and Shore 

The manner of making and fixing these byssii is not 
greatly unlike the method of the garden spider in 
spinning its web. Although it has acquired a stationary 
habit it can shift its location when the spirit impels it. 
When it wishes to move, it fastens a few byssii well out 
in the direction it intends to travel; then, detaching 
those in the rear, it hauls itself forward by pulling upon 
the extended threads. But this is a slow, and seems to 
be, certainly, a laborious process; far too slow, in fact, 
to enable it to escape from its enemies, even though it 
tried. 

It is hard to conceive a more monotonous existence 
than that led by the mussel. It would almost seem 
that the excitement of a violent end would come as a 
welcome in such an eventless life. Beyond gently open- 
ing and closing its valves, it seldom displays any ac- 
tivity; but even this movement has its limitations. The 
valves never open very wide — no more than to make a 
goodly sized slit in which can be seen the rich reddish 
brown velvety fringe of its fleshy mantle. 

From this it will be readily surmised that there is 
nothing spectacular in the moon snail's attack on this 
unresisting creature. The excitement and action which 
mark the chase of most predatory marine animals are 
utterly absent here. The aggressor simply approaches 
its victim, folds its capacious foot and mantle around 
it, completely hiding it from sight, and remains im- 
mobile for the greater part of an hour. After which 
it releases its hold and glides away to bury itself in 
the sand. 

Yet, notwithstanding the apparently easy manner in 
which the moon snail captures its food, its method is 



The Moon Snail 37 

not without interest. Nor should it be assumed that 
this peaceful process is devoid of effort. Although not 
noticeable to the eye, when this animal has wrapped its 
slimy mass about its prey it is actively engaged in a 
frightful operation. 

It may as well be said at once that this mollusk is 
the most ruthless butcher on the floor of the sea. There 
are other animals which dispatch their victims in far 
greater numbers, but in point of refined cruelty and 
deadly technique the moon snail is easily the master 
executioner. 

In separating the shells of a mussel recently released 
by this carnivorous creature, we find the interior soft 
parts to have been nearly eaten away. Nothing re- 
mains but a few shreds of the fibrous attachment that 
held the animal to its hinged cell. It could not have 
been cleaner had the shells been scraped with a scalpel. 
Near the hinge, on one of the valves, is the telltale 
perforation whose white countersunk edge, contrasting 
with the dark exterior, show how the moon snail had 
reached its victim. Now the clean-cut bevel around 
this hole denotes the use of an extraordinary tool. 
This is in truth the case. The moon snail, in common 
with others of its class, possesses a drilling apparatus 
that is unique in the animal kingdom. 

The drill is contained in the proboscis, an organ 
ordinarily retracted within the mantle but capable of 
considerable extension. It is a curious implement, this 
drill. It is a transparent, ribbonlike band of horny 
texture, the surface of which is ornamented with rows 
of tiny teeth. The band itself is less than a thirty- 
second of an inch wide, and the teeth, or cusps, are not 



38 Dwellers of the Sea and Shore 

visible without the aid of a good lens. This boring 
apparatus is virtually a rasp armed with hundreds of 
abrading points. It is located well up in the proboscis 
and is brought into play through the peculiar ability of 
this organ to turn itself partly inside out, much in the 
fashion that the finger of a glove can be turned within 
itself. 




RADULA, OR RASPING ORGAN OF THE MOON SNAIL. (GREATLY ENLARGED.) 

Attached to the under side of the proboscis, near the 
end, is a soft circular pad. The presence of this at- 
tachment at once gives the clue as to how the moon 
snail penetrates the shell of its victim; for it seems to 
serve as a sucking disk, and by means of its holding 
power is the necessary purchase obtained to apply the 
pressure of the drill. 

But the most significant feature is the pair of cutting 
jaws just within the tip of the eversible proboscis. 
Each jaw is a thin platelike blade of irregular shape 
and is fixed so that it presents a razor edge to its com- 



The Moon Snail 39 

panion, both working upon one another somewhat like 
a pair of shears. This dreadful instrument is a most 
efficient accessory. It is by introducing this into the 
drilled aperture that the moon snail becomes a mon- 
ster. It literally hacks the helpless mussel to pieces. 
What really takes place is the deliberate fragmentation 
of the other. To be brief, the moon snail picks its prey 
out piecemeal. 

And yet there are phases in the life of this creature 
that have a saving element. Great as are its vices, it 
is not entirely removed from virtue. Indeed, to depict 
only the darker aspect of its instincts would be unfair. 
Therefore, I shall try to bring into relief, also, that 
element of grace to which it would, no doubt, wish to 
lay claim. This is its foresight and consideration as 
a parent. The mother, with a precision born of 
patience, constructs a protective cradle for her young 
that is a marvel of dexterity. 

Except for a difference in size, the female is in out- 
ward appearance exactly like her smaller mate. The 
mating season is in midsummer, and it is then that she 
makes her singular egg case. It resembles nothing so 
much as a thin, sand-encrusted, cracked saucer or bowl 
minus a bottom. Now the egg cases of the moon snails 
are familiar objects on many beaches; they are often 
washed ashore in thousands. Yet it appears that very 
few, except naturalists, are aware of their origin. But 
this ignorance on the part of the lay person is not with- 
out good reason. There is little about the egg cases to 
indicate their identity. Naturalists themselves, for 
that matter, have not been in the secret long. For, in 
works written in the past, but in a period when their 



4Q 



Dwellers of the Sea and Shore 



authors should have known better, we find unique de- 
scriptions, assertions that these are low forms of life 
belonging to various places in the animal kingdom. 

An examination with a strong glass will reveal the 
sandy surface to be a skillfully wrought protective shell, 



» 






4 

* 







EGG CASE OF THE MOON SNAIL. 



underneath which is a single layer of transparent glob- 
ular capsules. These are arranged compactly, but in 
a roughly quincuncial manner. So small are they that 
there are more than sixteen hundred in the area of a 
square inch. But, mind, these are not the eggs them- 
selves. The eggs are bodies still more minute. There 
are a dozen and more suspended freely in the humor of 



The Moon Snail 41 

each capsule. By careful and repeated measurements 
of the surfaces of sundry egg cases, I have computed 
the total number of eggs produced by the female in a 
single brood to be more than half a million. 

The building of the egg case is a painstaking proc- 
ess. More often than not, the greater part of a day 
is given to this maternal task. The capsules are glued 
together in the mantle cavity from whence they emerge 
in a gelatinous sheet. As fast as it is formed, however, 
the mother covers the agglutinant surface with selected 
grains of the sand in which she is generally half buried. 
As the case continues to grow, she holds it close to her 
shell. Consequently, it travels completely around her, 
being molded into its peculiar shape by its circuitous 
excursion. 

After the making of the case, the mother is no 
longer concerned with her young. She has labored to 
insure their protection during their incubation, but 
with this her interest ends. When her task is com- 
pleted she moves away, abandoning her brood at their 
birthplace. 

But she has done her work well, and the eggs have 
little need for further maternal care. For nearly a 
month the egg case is washed here and there over the 
sand and stones, and remains intact. Then the eggs 
are ready to hatch. And it is not until then that the 
egg case begins to crumble. The action of the waves 
assists in this disintegration; thus, at the same time, 
assisting in the liberation of the numerous progeny. 

But what an extraordinary progeny! Here is no 
graceful dome but a flattened spire. It is just the 
merest fragment of a shell. Nor is there a muscular 



42 



Dwellers of the Sea and Shore 



foot to plow the sand. Instead of a crawler, it is a 
swimmer, a little, indescribable, transparent speck of 
jelly cavorting about in the water. 

This is the larval stage. Thenceforward the young 
gradually assume a more snaillike appearance. It is 
well into the ensuing winter, however, before they can 





:* 

EGGS OF THE MOON SNAIL. (HIGHLY MAGNIFIED.) THE INDIVIDUAL EGGS CAN BE 
SEEN AS THE SMALL BLACK BODIES CONTAINED IN THE LARGER CELLS. 

easily be recognized for what they are. But by the 
time their further development obliges them to pursue 
their course on the ocean floor, many thousands will 
have perished by the way. 

What will happen to them, do you ask? 

Well, some will become food for the barnacle, the 
clam, the sea squirt, and a multifarious but hungry host 



The Moon Snail 



43 



of smaller creatures. But in the case of the majority, 
the finish will be in the stomachs of the selfsame 
mussels which serve as prey for the full-grown moon 
snail. 

Now, to a certain extent, the two mollusks which I 
have here reviewed, the mussel and the moon snail, 
may be taken as representative of their classes. That 
is to say, the one is largely typical of the bivalves, or 




FREE-SWIMMING LARY.E OF THE MOON SNAIL. (GREATLY ENLARGED.) 

pelecypods; the other is an example of the univalves, 
or gastropods. It is to be noted, however, that the 
habits of the various species within each class may 
differ considerably. For instance, not all pelecypods 
lead a stationary life ; neither do all gastropods live 
by preying. 

The pelecypod mollusks are, in fact, a very extensive 
group of animals which vary widely even in their struc- 
ture. It is to this group that also belong the clam, the 



44 Dwellers of the Sea and Shore 

scallop, the oyster, and other well-known edible shell- 
fish. Beside the name Pelecypoda, meaning "hatchet- 
shaped" foot, and which, by the way, is in many 
instances a misnomer, the term Acephala is used, indi- 
cating "without a head." Another name, Lamellibran- 
chiata, in reference to the type of gills peculiar to these 
animals, has also been employed. But the terminology 
of science contains no name more descriptive or correct 
than the easily remembered, easily pronounced, and 
easily understood popular name "bivalve." Fjr every 
animal in this class has two valves (the word "valve" 
meaning "shell"). 

Bivalve mollusks, unlike their univalve brethren, do 
not build egg cases. They do, however, lay eggs. 
These, as a rule, are not kept within the shell among the 
fleshy folds, and when they hatch they give rise to free- 
swimming young somewhat similar to those of the 
moon snail. The fate of the majority is likewise sim- 
ilar. It has been asserted by naturalists that probably 
not more than one in a million reaches maturity. 

On the whole, the bivalves have acquired a more 
stationary habit of living than the univalves, but there 
are individuals among the former which can travel with 
remarkable rapidity. In speed and action the fastest 
univalve cannot match them. The scallop (Pecten) is 
one case in point. It adopts the singular method of 
quickly opening and closing its valves; thus propelling 
itself through the water in a jerky, butterfly sort of 
flight. The extreme case, though, is to be seen in the 
razor clam (Solen ensis) . The characteristic "razor 
shell" of this odd-looking mollusk is familiar to every 
one who has visited a sandy beach. They are easily to 



The Moon Snail 45 

be collected by the hundreds. But to get specimens of 
the living animal is quite another matter. Burrowing 
in the sand to the depth of two or more feet, where 
they remain hidden most of the time, they are seldom 
seen. Yet even where one can be observed incautionsly 
projecting from its burrow, it is not so readily cap- 
tured. At the slightest jarring of the sand in its neigh- 
borhood, it takes alarm and immediately disappears. 
And it requires a rapid and skillful digger with a spade 
to catch up with it. Its quick descent in the sand is 
accomplished by means of its remarkable foot. This it 
extends downward into a point; then expanding the tip, 
the organ becomes wedged in the sand, enabling the 
animal to draw close the shell; and by this perform- 
ance, quickly repeated, the razor clam makes a speedy 
retreat. Now sometimes the razor clam likes to take a 
swim. Here, too, the efficiency of its foot is displayed. 
With a flick of this organ the animal pulls itself spas- 
modically but swiftly through the water. 

Although all bivalves are pelecypods, not all uni- 
valves are gastropods. (The word "gastropod" means 
"stomach foot.") Only two mollusks, however, are 
exceptions to this statement. These are the tooth 
shells, or Dentalla, and Nautilus, which belongs to 
those divisions known as the scaphopods and cephala- 
pods, respectively. So in the strict sense of the word 
the term "univalve" has its limitations, but as it has 
come into such common use in reference to the gastro- 
pods, its employment is now generally restricted to 
these mollusks. 

Now I have been so lavish with strange names and 
scientific terms that the reader is apt to have become 



46 Dwellers of the Sea and Shore 

confused. Let me, therefore, hasten to set him right. 
It will be easy to do this by summarizing. 

The Mollusca are divided into five classes. These 
classes, taken in the order of their supposed relation- 
ship, are respectively the Amphineura, Gastropoda, 
Scaphopoda, Pelecypoda, and the Cephalopoda. With 
the exception of the Amphineura, a group that includes 
the curious chitons and their allies, the modification of 
the foot is the basis on which these classes have re- 
ceived their various names. For it will be noticed that 
the terminations of the remaining four names refer to 
the foot. Thus, the Gastropoda, represented by the 
common garden snail, the moon snail, the periwinkles, 
and other mollusks bearing but one shell, usually 
spirally coiled, crawl on the thickened under surface of 
their bodies. That is to say, the foot. The Scapho- 
poda, whose shells are like little elephant tusks open at 
both ends, burrow in the sand or mud with a long 
wormlike foot. The Pelecypoda, to which belong the 
familiar oyster, clam, and mussel — bivalves all — are 
variously endowed in respect to the shape of foot, but 
the prevailing type is club- or hatchet-shaped. The 
Cephalopoda are distinguished among molluscs by 
having the foot modified into a number of so-called 
"arms" which encircle the head or the mouth. It is 
to this group that the squid, the octopus, and the pearly- 
shelled, chambered nautilus belong. 

It is the class Gastropoda, however, that is the 
largest and most comprehensive of the five subdivisions. 
It far outnumbers the others, both in species and indi- 
viduals. Moreover, it is among these that are found 
the only members of the entire group of mollusks which 



The Moon Snail 47 

have learned to breathe in the open air. The garden 
snail and the slug are outstanding examples. Once 
upon a time these quaint creatures were possessed of 
gills and lived in the water, like their relatives in the 
pond and sea. But now they breathe with lungs, and 
they are no more able to live under water, contin- 
uously, than any other air-breathing animal. The 
question, therefore, at once arises as to how this 
transformation was brought about. How, in the evo- 
lutionary progress of these creatures, came they so 
completely to change in their habits? 

The truth is, no one knows. But men of learning 
have given this question considerable thought. And 
they have formed some very definite opinions. They 
have, moreover, given us evidence that greatly supports 
the apparent probability of their conclusions. One 
aspect of this evidence is well worth pausing here to 
ponder. At any rate, in so doing, it will enable us to 
get an interesting viewpoint of this problem. 

This brings us again to the tides. As we have seen, 
the periodic rise and fall of the waters leave many ani- 
mals exposed for a greater or lesser duration of time. 
Now there is much variation between the capacities of 
different shore animals to resist drying when exposed 
by the retreating tides, but these capacities are invar- 
iably in direct relationship to the positions the animals 
occupy on the shore. Thus, certain of the periwinkles 
(Littorinidtf) are found only high above the low-tide 
line. Some (L. neritoides) live in shady nooks just 
above high-tide mark. But there are some tropical 
members of this family (L. varia, L. fasciata, L. pul- 
chra) that actually live in trees entirely out of reach 



48 Dwellers of the Sea and Shore 

of the salt water. It will be seen, therefore, that the 
Littorinas are well on the road toward a land life. 
They are, in fact, gradually substituting lungs for gills. 
That the Littorinas first acquired the habit of living 
out of the water through the influence of the tides is not 
unreasonable to assume. And succeeding centuries 
gave rise to individuals which were increasingly able to 
withstand long exposure to the air. But, while this 
may hold good in the case of this particular group 
which is essentially marine, there would seem to be 
some difficulty in accounting for those air-breathing 




littorina; a periwinkles shell. 



types which undoubtedly had their origin in fresh 
water. And those types, by the way, have so far pro- 
gressed that they must have been a long time, on the 
road; in fact, the first to start in the evolutionary pro- 
cession. 

But the answer to this is forthcoming. It is pre- 
sumed that the age of the ocean since the earth 
assumed its present form is somewhat less than ioo,- 
000,000 years. Now, as is well known, the sea re- 
ceives from the land in addition to other elements more 
than 60,000,000 tons of sodium every year. This sub- 
stance, dissolved out of the rocks by rains and carried 



The Moon Snail 49 

in solution to the ocean by rivers and underground 
streams, there unites with its proper proportion of 
chlorine, the chemical union forming the salt of the sea. 
It becomes obvious, then, that as we go farther and 
farther back in point of time, the primordial waters 
become rarer and rarer in those earth-derived elements 
that make up the content of the present existing sea. 
In other words, to put it conversely, the sea became 
more salty with each succeeding age. Therefore, it 
is extremely probable that the early mollusks had their 
beginning in a fresh-water sea. And then, also, of 
course, as well as now, the tides prevailed. 



Chapter IV 
THE STARFISH AND ITS KINDRED 

It is a curious fact that of all the great groups, or 
phyla, of animals which inhabit the sea, there is only 
one which is purely marine, which has no relatives or 
representatives on land. This singular instance is in 
that division of animals known as the spiny skins, or 
echinoderms : under which are classed the starfishes 
(Asteroidea) , brittle stars (Ophiuroidea) , sea urchins 
(Echinoidea) , sea cucumbers (Holothuroidea) , and 
feather stars and sea lilies (Crinoidea) . Where, for 
instance, the lobster, the jellyfish, and the horseshoe 
crab are related to the terrestrial crayfish, the fresh- 
water hydra, and the garden spider, respectively, we 
find the starfish and its kindred to have not the re- 
motest connection with any living forms out of the sea. 

The starfishes are common to nearly every seacoast 
in the world. The most numerous species along the 
Atlantic shores of this continent are Asterias vulgaris 
and A. forbesii; the first named being found from the 
Carolinas to Labrador, the second from Massachusetts 
Bay to the Florida keys. They are nearly alike, except 
that the rays of the former are more pointed and the 
madreporic tubercle is of a uniform color with the rest 
of the animal. In the latter this tubercle is orange- 

50 



The Starfish and Its Kindred 51 

colored. Traveling in droves, as starfishes sometimes 
do, they range from low-water mark to depths of six 
hundred fathoms or more. 

The brittle stars are so called because of their ex- 
treme tendency to break off their limbs when captured. 
They are much less abundant than the common star- 
fishes, and their secretiveness makes them hard to find. 




ASTERIASJ THE COMMON STARFISH. THIS INDIVIDUAL IS GROWING A NEW ARM IN 
THE PLACE OF ONE THAT WAS LOST. 

Although some specimens live near the shore, they are 
for the most part inhabitants of deep water. Their 
very slender rays and their active wriggling move- 
ments give them the superficial appearance of a spider. 
Their outstanding difference from the starfish, how- 
ever, is in having their limbs more or less loosely at- 
tached to the central disk, or body. In the starfish 
the rays are solid extensions of the disk. 

Sea urchins, although differing in shape, are alike in 



52 Dwellers of the Sea and Shore 

having no rays. Moreover, all are characterized by 
the great development of movable spines. They are 
sometimes called ocean hedgehogs, on account of their 
spiny covering. More sluggish than the starfishes, 
they seldom wander far from their accustomed haunts. 
Various species of these animals are found from high- 
tide mark to very great depths. 

Sea cucumbers are creatures whose general appear- 
ance is wholly unlike the starfish and the sea urchin. 
But there are certain characteristics (of too technical 
a nature to be detailed here) they have in common with 
those animals which places them undoubtedly in the 
same company. They may roughly be described as 
sausage-shaped with a rosette of tentacles at one end. 
They are inhabitants of every variety of bottom; but 
the majority are found in the sand and mud which, like 
the earthworm, they eat for the organic particles there- 
in contained. 

Most feather stars and crinoids live only in deep 
water and are seldom found near the shore. The cri- 
noids are generally known as sea lilies because of their 
general form. They have a long, jointed stalk, one end 
of which is attached, while the other bears the disk and 
featherlike arms of the animal. The sea lilies remain 
permanently fixed where they grow, but the feather 
stars, which at one stage of their life are stalked, de- 
tach themselves from this part of the body and swim 
about by means of their arms. 

Thus I have given in the briefest form possible the 
general characteristics of the five classes of animals 
which make up the phylum Echinodermata. The com- 
plete life histories of by far the greater part of this 



The Starfish and Its Kindred 53 

interesting and extensive group are as yet unknown. 
Indeed, even the full details regarding the lives and 
habits of our commonest forms are still unrecorded. 
For the young naturalist who is fired with the ambition 
to add his substance to the sum of scientific knowledge, 
he can not do better than to apply himself to the study 
of whatever type is at his convenience. 

But this matter of convenience entails more than the 
mere presence of the subject in one's locality, if one is 
successfully to enlarge upon the knowledge of its ways. 
It is often that chance brings discoveries which perse- 
verance has failed to produce; and that physical con- 
ditions for observation may also determine the 
measure of achievement. As a case in point, let me 
take the reader to a once favorite haunt of mine. 

Formerly, in the vicinity of Harbor Beach, there 
stood well out in Hempstead Harbor the partly sub- 
merged framework of an old wreck. It had been a 
coastwise boat that years ago, on catching afire in the 
Sound, put into this harbor where she was beached and 
left to burn to the water's edge. When I first made 
its acquaintance, all that remained was the bulkhead, 
which w r as headed toward the shore, and a score or 
more of ribs still standing upright and trailing away 
from this point, those outermost finally losing them- 
selves in the deeper water. The superstructure, of 
course, had entirely disappeared. Little remained but 
the bare skeleton of what once was evidently a well- 
built boat. 

However, at that juncture w T here the keel and other 
timbers form the framework of the bow, there was 
yet in position a portion of the forecastle deck. This 



54 Dwellers of the Sea and Shore 

was of a size just roomy enough to serve as a vantage 
point from which to view the details of the interior of 
the ancient wreck. The angle at which the hull settled 
was such that the greater part of this shelving wood- 
work was above the reach of the tides. 

Between the tide marks — that is to say, in the space 
of about seven feet — the framework was covered with 
mussels. But their possession of the blackened timbers 
was disputed by the barnacle and the shipworm; for the 
fragmentary appearance of the hull showed clearly the 
presence of this invisible but insidious last-named ani- 
mal ceaselessly gnawing at the vitals of the woodwork. 
In the higher levels of the transparent waters, every 
stick and stanchion stood out distinctly. From every 
part of the submerged structure there rose fronds of 
seaweed and hairlike clusters of hydroids. In the dark- 
green limpid depths could be seen dull-glowing patches 
of red, like splashes of molten iron beginning to cool. 
They were sponges; and their vivid hues invested the 
homely old hull with an exotic charm. Many bizarre 
forms were represented there. From the ascidians, or 
sea squirts, which looked like warty growths, or excres- 
cences, on the wood, to that delightful creature, the 
starfish, which is an adornment to whatever surround- 
ing it may be in, the profusion of forms seemed to be 
as infinite as it was various. 

Such is the general, and necessarily imperfect, pic- 
ture of what, to me at least, was a marine paradise. 
Whether or not this mass of rotten wreckage would 
have excited in others the same emotions that filled me, 
I do not know. But many were the splendid hours that 
fell to my lot as I lay under the summer sun peering 



The Starfish and Its Kindred 55 

into those mystic depths. Majestic, rapturous hours! 
Strange fishes slinking out of the shadowy maze, catch- 
ing sight of my slightest movement, retreated ghost- 
like into the deep blue. Others, less timorous, 
dissolving into view would hover near, apparently un- 
daunted by my presence. Often, however, I would 
frighten them w T ith a wild flourish of my arms to see 
how T far the silvery gleam of their scales could be fol- 
lowed into the emerald depths beneath. And how al- 
luring were those crystal waters ! Frequently I would 
dive down into the inviting coolness of the limpid laby- 
rinth to sit on some frond-w T reathed beam as long as 
the breath within me lasted. 

But that delightful rendezvous no longer exists. 
With the exception of some half dozen rotting timbers 
which are exposed at low tide, the hull has since dis- 
integrated and its water-logged fragments are being 
fast silted over on the harbor floor. It was not the 
force of wind and waves, however, that brought 
about its reduction, for this is a well-protected in- 
let; the factor was far more subtle, but none the less 
puissant. 

It is well known that the destruction of maritime 
property by the shipworm {Teredo) is surpassed by 
that of no other marine organism. Though com- 
monly called the "shipworm," this creature is not a 
worm ; it is a mollusk; that is to say, a near relative of 
the clam, the moon snail, and other shellfish. Its 
wormlike form is due to its boring habit. Each female 
is capable of spawning about a million young; and 
these, unlike the adult which remains fixed in its bur- 
row for life, are very active swimmers. When they 



56 Dwellers of the Sea and Shore 

grow to the size of a pinhead they seek lodgment on 
pilings and other submerged timber, and there start 
their burrows. For a short distance from the entrance, 
each burrow is perpendicular to the surface; it soon 
turns, however, and aligns itself with the grain of the 
wood, although with more or less of a twist. Regard- 
less of how numerous these burrows may be, the occu- 
pants never touch each other. Always there remains 
a thin partition between the individuals infesting the 
wood. The shipworm mines its tunnel to accom- 
modate its growth. As the burrow increases in length 
it increases somewhat in diameter, but the original 
point of entrance always remains the same. This open- 
ing is so minute that it easily escapes notice and the in- 
festation is generally not detected until the destructive 
work of the animal is well advanced. It is through this 
orifice that the shipworm thrusts out its paired, siphon- 
like tubes to strain the water for food. 

Ever since man began to build ships and wharves 
he has had to contend with this diminutive monster. 
So effective are its ravages that it can ruin utterly 
within the space of a few months that which takes 
years of labor and millions in money to construct. In 
the upper part of San Francisco Bay the damage dur- 
ing the years 19 19 and 1920 resulting from the activi- 
ties of the shipworm has been estimated to exceed 
$15,000,000. This estimate was placed solely on the 
damage to docks and piers; what the total losses to 
shipping and harbor construction of all our ports dur- 
ing every year may be is not determined; it is agreed, 
however, that the amount is so stupendous that its 
significance would be lost on the average mind. Here- 



The Starfish and Its Kindred 57 

tofore the greatest losses seem to have been sustained 
on the Pacific coast. Whether this has been due to a 
greater proportion of wood structures in those waters 
which were subject to infestation, or whether it was 
due to other natural conditions, is not clear; at any 
rate, there has been a striking increase in the preva- 
lence of this pest in the shore waters of the Atlantic 
coast. It has, in fact, made its appearance in extraor- 
dinary numbers in all congested harbors along the 
Eastern seaboard as far north as Long Island Sound. 
Within the next few years, at its present rate of in- 
crease, it will have established itself in every seaport 
and harbor in the United States. 

It threatens not merely man's property, however; 
it is a real and constant menace to his life. Indeed, I 
think it may be said without exaggeration that indi- 
rectly the shipw r orm has sent more men and boats to 
the bottom of the sea than have been wiped out of 
existence by the direct violence of storms. 

However, the destruction of the old hull was com- 
pensated for by its picturesque appearance and the 
fantastic beauty that the living forms lent to its 
vanishing shape. But, although the beauty of the spot 
was quite irresistible, other attractions also took me 
there. From my station on the little platform, I could 
study with the greatest ease the habits of my favorites 
in their natural surroundings, and follow the growth 
and succession of various types as these were mani- 
fested throughout the different seasons. It was, in 
truth, an ideal observatory. 

Ndw, needless to say, the starfish, which in point of 
numbers was second only to the mussel, engaged a 



58 Dwellers of the Sea and Shore 

large share of my attention. If you know the starfish, 
you will readily guess why it elected to make this place 
its home. It was because of the ever-constant supply of 
food covering the crumbling ribs. But as this history 
is being written primarily for the reader who knows 
little or nothing of our sea folk, I shall amplify the pre- 
ceding statement; there is more of interest in it than 
the bare assertion implies. And as I proceed toward 
this end, we may find it of further interest occasionally 
to linger by the way. 

Once again I see myself installed in the spot beloved 
of Asterias. The late September sun blazes through 
a listless air that as yet gives no hint of the frigid days 
which are soon to follow. But the heat, so oppressive 
on shore, is here tempered, not by zephyrs from the 
Sound, for there is not the slightest ripple in the harbor, 
but by the colder expanse of surrounding water. The 
tide is rising and has nearly reached its highest 
level. 

Starfishes awaiting the return of the tide can be seen 
everywhere : some are crammed in crevices, others 
have wedged themselves in companies of several into 
nooks that would apparently limit the free move- 
ment of a single individual, and not a few are sus- 
pended motionless by the tip of a single ray from the 
under side of the dripping bulwark. These stragglers, 
slowly moving at best, while having been intent on their 
various occupations near the high-water mark, were left 
behind by the falling tide; and now, incapable of ef- 
ficient locomotion out of their natural element, they 
remain inactive until its return. In the water below, 
seemingly scattered more numerously than the stars in 



The Starfish and Its Kindred 59 

the sky, starfishes in various stages of growth are cling- 
ing to or crawling over the mussel-laden framework. 
By the bright orange button, or madreporite, near the 
center of each animal's back, and which each individual 
without exception carries, I recognize them all as be- 
longing to the same species, Asterias forbesii. 

Directly beneath, just within reach, I see one un- 
usually large creature. It measures easily a foot across. 
Although long familiar with the appearance of As- 
terias, I cannot refrain from lifting this interesting 
specimen to examine for the thousandth time its curious 
details. For, be it known, the starfish is in many re- 
spects unique among animals. Simple as it is con- 
structed, it is a never-failing object of wonder to the 
novice and to the experienced naturalist alike. 

Perhaps its most outstanding departure from other 
animals is in the method of its locomotion. Laying this 
creature upon its back, I observe its efforts to right 
itself. It would seem that on account of its rigid struc- 
ture it would have some difficulty in accomplishing this 
feat; but it can, in fact, perform some remarkable con- 
tortions in spite of its apparent inflexibility. For a few 
moments it remains the picture of helplessness. Flank- 
ing the deep groove that starts at the mouth and ex- 
tends along the middle to the tip of each of its five rays 
is a forest of little transparent tubular processes. 
These slender processes are about three-fourths of an 
inch long, contractile, and very elastic; they are termi- 
nated by a well-formed sucker, an expansion by means 
of which they can be firmly fixed to any solid surface; 
they are, in fact, the ambulacra, or so-called tube feet, 
which are the actual organs wherewith the animal 



60 Dwellers of the Sea and Shore 

moves about. Now in turning over, it brings its tube 
feet effectively into play. Twisting one or more of the 
rays on one side until their tips are bent under the body, 
so to speak, the tube feet at the extremities are thereby 
enabled to get a hold of the wood of the platform. 
Then by the successive attachment of the tube feet fol- 
lowing farther inward on the rays, the starfish pulls its 
bulk gradually but completely over. The whole move- 
ment occupies a little less than a minute. 

Beyond this effort, it makes no further attempt at 
any extensive maneuvering. Seemingly unable to use 
its sucking feet on a dry surface, it remains on the spot 
now well wetted by its dripping body. Yet its pertur- 
bation at being out of its natural element is quite mani- 
fest. On the under side of the tip of each ray can be 
seen a tube foot, noticeably delicate and without a suck- 
ing pad, extending here and there and then retracting, 
as though carefully exploring the region within its im- 
mediate radius. This operation is strongly suggestive 
of a blind person feeling around with a cane. Nor is 
the comparison incapable of further development. For, 
although able to distinguish light from darkness, the 
starfish is, in the usual meaning of the term, blind; but 
the suckerless tube feet are in every sense of the word 
its feelers. These latter, by the way, in spite of their 
resemblance to the true tube feet, are never employed 
as such ; they are used only as organs of touch. Strange 
— is it not? — that this creature has five eyes — one at 
the extremity of each ray, a minute crimson speck — but 
cannot see; is equipped with multitudinous feet, but is 
unable to progress faster than three inches in a minute. 
Nevertheless, notwithstanding its limitations, it tra- 



The Starfish and Its Kindred 61 

verses considerable distances; and to one unaware of 
the method of travel, its migrations are accomplished 
in an incredibly short time. The truth is, it appears 
rather poorly favored when compared with other 
rovers; but it gets there just the same, as we shall pres- 
ently have an opportunity to see. 

Before replacing my pretty starfish in the water, 
I do not neglect to examine its upper surface for 
caprellas and sea spiders and other minute creatures 
which are sometimes harbored there. Ofttimes this 
proves to be a profitable hunting ground; but in this 
instance it is barren of these guests. All that is re- 
vealed under the searching scrutiny of my pocket lens 
is the dark-purple exterior armed with short, blunt, 
calcareous nodules, or spines. They are encircled at 
the base, and not infrequently covered, by a cluster of 
tiny pincerlike appendages. These are the pedicellarise ; 
they are plainly adapted to seizing and holding, and 
their principal use seems to be to rid the animal of 
foreign substances such as certain seaweeds and other 
growths that have a tendency to affix themselves to 
hard objects. Less conspicuous, because of their great 
transparency, are numerous teatlike projections arising 
between the spines, which form part of the breathing 
system of the starfish. Except for their smaller size, 
they somewhat resemble the tube feet minus their suck- 
ers. Bending to and fro, they are constantly in motion, 
seeking to extract the oxygen necessary for the animal's 
support from the surrounding film of water. Thus it 
will be seen that the starfish veritably carries its lungs 
on its back. 

But the most striking thing, in appearance at least, 



62 Dwellers of the Sea and Shore 

is the brilliant orange tubercle called the madreporite. 
Lying near the rim of the central disk, at the angle of 
two of the rays, this rounded prominence is set out in 
vivid contrast to the rest of the body. Its gaudy color 
and exquisite conformation make it no mean adornment 
to the otherwise rugged exterior. It is a miniature 
replica of some exotic brain coral. In structure it is 
porous. It is, in brief, a filter. Its purpose is to strain 
the water which is taken in by the starfish and used to 
distend the tube feet when it walks. 

Lifting Asterias from the platform, I drop it into 
the water and watch it sink slowly toward the bottom 
where it becomes nearly lost in the dark haze that all 
but obscures the verdant floor. Its position, however, 
is marked for a few moments by an ascending shower 
of bubbles, greenish-cast pearls arising in diminishing 
numbers to break at the surface with sparkling bright- 
ness. The soft, pleasing murmur of the bursting beads 
finally dies out and my attention is directed to the more 
visible parts of the hull. It immediately becomes evi- 
dent that something of more than usual significance is 
taking place. Several feet below the mussels I see a 
number of starfishes clinging to the timber with their 
backs humped in the characteristic manner they assume 
when enveloping food. 

What can they be eating? What is it that they have 
found in that region where only fixed vegetation seems 
to flourish? Certainly they cannot be vegetarians. 
And as for the presence of anything else of an edible 
nature, I am too familiar with this portion of the hull 
to have allowed it to escape me if it exists. Further- 
more, it is impossible that they are enjoying a meal 



The Starfish and Its Kindred 63 

which was obtained elsewhere; for starfishes are never 
known to transport their food; they devour it on the 
spot. Poising myself far over the edge of the platform 
to get a better view, I peer intently at the spectacle. 
No, nothing edible is to be seen in the vicinity. But 
under several of the nearest animals can be detected 
a filmy exudation appearing between the rays. It now 
becomes plain what they are about. Their attitudes 
are indicative of but one thing: they are spawning. 
These are females and they are liberating their eggs in 
the water to be fertilized by the male sperm cells, which 
are no doubt swarming here in invisible millions. Al- 
though the sexes are distinct it is next to impossible to 
tell from outward appearance which is the male and 
which is the female starfish. However, knowing it to 
be the rule among most low orders of animals that 
when an event like the preceding is taking place, the 
males are generally not far away, I look around to see 
if any unusual activities on the part of the others are to 
be seen. But nothing noteworthy manifests the fact 
that the males are busy. 

Time passes. I am anxious to see what part the 
males play, if any, in bringing this wholesale delivery 
to a successful issue ; for there is good reason to suspect 
that they are not wholly indifferent to the travail of the 
females. Although chance to a large extent determines 
the actual meeting of the eggs and the sperms, it would 
be a rare thing, indeed, if this chance were not lessened 
by the mutual behavior of the parents. But it grows 
dark; the tide is falling; I am reluctantly obliged to 
give up my watch. 

Nevertheless, the next day finds me ensconced in the 



64 Dwellers of the Sea and Shore 

same place ready to unravel whatever threads may 
present themselves. And I am compelled to add that 
repeated observations day after day bring me nothing 
new; each time I see the usual performance of the 
females but nothing to denote that the occasion is sig- 
nificant co the males. Yet my perseverance is not en- 
tirely without reward. I am soon to have more than 
my pains for my laborious steadfastness. But let me 
anticipate myself. Complete and successful observa- 
tion of this affair is yet to be mine. However, in the 
following occurrence there is more than enough to con- 
vince me that if my suspicions are not altogether well- 
founded, I have come close to something so significant 
that it dwarfs the interest of the present inquiry. 

Late one day w T hen getting ready to abandon my 
post, I was arrested for a moment by something moving 
deep down in the bottom of the hull. It did not hold 
me for long, as it immediately lost itself in the gloom, 
and in the imperfect light I took it for some drifting 
clump of seaweed carried along by the incoming tide. 
Gathering together my trappings I climbed down to my 
little skiff which was moored to one of the stanchions 
in the capacious hull. No sooner had I seated myself 
than I perceived my mistake. The water was low, and 
my position in the boat afforded a nearer view of what 
was going on below. In the tenebrous depths moving 
in the general direction of the current could be dis- 
cerned light, irregular masses outlined against the 
darker bottom like nimbus clouds in the moonlight. 
One of these patches carried upward well within visible 
range revealed its nature. It was a cluster of star- 
fishes, each hanging on to the other. Then it was I 



The Starfish and Its Kindred 65 

saw that the wreckage was fast becoming covered with 
them. They came singly and in groups; they came in 
multitudes. From whence they came I do not know; 
however, it is not improbable that the oyster beds near 
the mouth of the harbor would show evidence of their 
recent presence. Moreover all arrived by the same 
means. They were swept along by the tidal movement. 

But why this exodus? Why this visitation to a spot 
which can give bare support in the way of food or foot- 
hold to such enormous numbers? Well, my guess is that 
this gathering of the clan had not to do with food but 
with fertility. It was one of those instances, not uncom- 
mon in the watery world, wherein marriageless females 
are nevertheless accompanied on their travels by at- 
tentive males. 

Let us see. From the time the young starfish hatches 
out of the egg until several weeks later when it settles 
to the bottom, its appearance and its habits are totally 
unlike those of the familiar adult. It is a transparent 
cluster of fingerlike processes, so minute as to be barely 
visible; and it swims by means of short vibrating hairs, 
or cilia, which cover its body. During this period it is 
carried about by the tidal currents and waves or, as is 
more frequently the case, it holds close to the shelter 
of rocks, shells, seaweeds, and other nooks in the vicin- 
ity of its birthplace, thus lessening its chance of being 
swept out to the open sea where it would ultimately 
perish for want of proper food. But when the time for 
the metamorphosis arrives, when it loses its early, or 
larval, form and becomes a perfect, though tiny, star- 
fish, it is no longer in danger of being carried out to 
sea; it is enabled to cling fast to solid objects with its 



66 Dwellers of the Sea and Shore 

little tube feet. At this time, however, another and 
perhaps more serious problem presents itself; it must 
find food of such a nature as easily to be captured and 
overcome by such an insignificant and slow-moving mite 
as the starfish now is; for it starts out in the final stage 
of its life no bigger than a lentil. Herein is the first 
clue to the reason for the migrating of the sexes. No 
region of the ocean is more prolific of life than the 
shallower waters near the shore and in coves and inlets; 
and no region is more diversified. In that zone, from 
the high-water mark to a point several fathoms deep 
the sun's rays help to produce the greater part of that 
vegetation to which nearly all living marine animals 
owe their existence either directly or indirectly. This 
is to say the plants are eaten by certain animals which 
are in turn devoured by other creatures and these again 
may become food for others. Therefore it is not with- 
out purpose that the gravid females leave the less favor- 
able depths to assemble in the region of the sunken 
wreck. In response to the maternalistic instinct they 
seek to disperse their eggs in surroundings where food 
will be plentiful for the forthcoming progeny. The 
adult males, in response to an instinct no less powerful, 
accompany the females in these migrations. For with- 
out their presence, without the certainty that the spawn 
is soon to receive that vital impetus which assures its 
further development, it is clear that the precautions of 
the prospective mothers will have been in vain. 

Would you know what the young starfishes eat? 
Well, to enumerate all the things that go to make up 
their diet would be somewhat difficult; for, like the 
adults, they are scavengers — although fastidious ones 



The Starfish and Its Kindred 67 

— and will hardly refuse anything which the taint of 
putrefaction has not made offensive. Although I have 
never observed them to touch marine plants even when 
starving, I have had no trouble in feeding healthy in- 
dividuals in various stages of growth pieces of apple, 
pear, and other acid fruits; provisions strange and 
foreign to their natural larder. But, also like the full- 
grown animals, the little ones prefer living food. This 
they find chiefly among the young barnacles and mussels 
and other small shellfish. 

Were it not for the gruesomeness of the operation, 
the manner in which they open the shells of their vic- 
tims would excite admiration; for their perseverance is 
without parallel. Indeed, to one who knows the star- 
fish only as an inactive, harmless, beach ornament, it 
will come as a surprise to learn that it can pull apart 
the valves of any shellfish its arms can encompass. The 
method is always the same. Straddling a bivalve, it 
humps itself high in the center, and fastens its hundreds 
of suckerlike tube feet to both valves. Then com- 
mences a steady pull. It is in reality a tug of war: the 
victim in the one case exerting its strength to keep its 
compartment tight-closed, and the starfish in the other 
slowly straining to force it open; but the starfish always 
wins. The luckless occupant cannot endure the con- 
stant pull. The starfish seemingly is tireless and finally 
the shell gapes open. Then an amazing act takes place. 
From out of its mouth the starfish protrudes its 
stomach, and envelops the animal within the shell. 
Nor does it withdraw this remarkable organ until its 
prey has been fully digested. 

This concludes the essential part of my observations 



68 



Dwellers of the Sea and Shore 




STARFISH SEARCHING FOR FOOD. (PHOTOGRAPH TAKEN ON THE BOTTOM OF A 

TIDE POOL.) 



of the common starfish as they were made in the old 
hull. Subsequent experience gained in other places and 
under other conditions has confirmed but not added to 



The Starfish and Its Kindred 69 

the substance of what I learned among its wormy beams 
and stanchions. Here also must end the reader's 
acquaintance with that structure itself. My purpose in 
introducing him to this haunt has been fulfilled. Be- 
sides the background it has given us for the activities 
of the starfish, it furnishes a very important object 
lesson. To the seashore naturalist, no object, whether 
it be floating driftwood or submerged piling, is un- 
worthy of attention. Whatever the tides inundate, 
regardless of its character, becomes fertile ground for 
him who deigns to dig. 

Notwithstanding my obligation to proceed in the 
business of presenting those others who properly and 
justly claim a share in this history, it is not without 
regret that I leave this lovely scene. I fain would 
linger over its pleasing memory, over the image of its 
thousand stars bespangling the moldering framework 
or decorating the darkness of its receding depths, over 
the recollection of those fruitful, rapturous hours, oft- 
times extending far into the night. To me this spot was 
as alluring in the blackest midnight as under the noon- 
day sun. For, with the fading of the day, it had an 
ethereal splendor all its own; yet not unearthly, or 
unreal. The framework faintly glowing with a mellow 
light of phosphorescence became softly outlined in the 
watery void. And in the vastness of the silent night, 
the ancient corse no longer was a thing of rotting 
wood and wormy recesses; it was near and dear and 
human ! 



Chapter V 

THE COMB JELLIES AND OTHERS 

If one would fully acquaint himself with the various 
activities of the animals which frequent the shore, he 
should not neglect to visit this region after nightfall. 
Then it is, when the terrestrial world has settled to 
rest, that the water becomes the scene of a singular ani- 
mation. On land, the setting of the sun is for the 
great majority of animals a silent signal for slumber. 
It is quite different with the creatures of the sea. With 
the exception of fishes and certain other higher forms, 
it is extremely doubtful whether marine animals sleep; 
and even in the case of those that are known to do 
so, it is the period of daylight rather than of darkness 
that they choose for this purpose. Throughout the 
night many creatures come close to shore in search 
of prey and retire before dawn. Observation at this 
time is comparatively easy; for if one be provided with 
a small electric flash lamp he can draw close to many 
wary crawlers, or stand quietly watching others which 
are utterly impossible of approach in the broad light of 
day. They seem not to be disturbed by the presence of 
the light; indeed, its rays are an attraction to not a few 
fishes, which disport themselves in glittering shoals 
within the luminous circle. 

70 



The Comb Jellies and Others 71 

Although no season of the year is without its social 
activities, it is on warm summer nights that these are at 
their greatest height. During the dog days, the genial 
temperature of the shore waters makes conditions par- 
ticularly favorable for the growth of plant life; this 
is reflected in the increasing abundance of animals, all 
of whom are ultimately dependent on the vegetation of 
the sea for sustenance. Moreover, the spawning of 
most shore dwellers takes place at this time, and as a 
consequence the water becomes extraordinarily popu- 
lated. There is plenty to eat for all. 

And how well they know it! Making their way in 
droves from the outlying reaches, the spider crabs 
(Libinia emarginata) approach the shore or swarm 
over the mussel banks, sometimes so thickly that the 
bottom seems literally covered with them. They live 
mostly on vegetable matter. These crabs are well 
named; they look like giant spiders, with their flask- 
shaped bodies and remarkably long, slender legs. The 
males are the larger, and often have a spread of over 
a foot and a half. Not only are these creatures the 
largest of all the true crabs to be found along our 
coasts, but another one of the spider crabs (Macro- 
cheira kcimpferi) , found in Japanese waters, is easily 
the largest living crustacean of the world, measuring 
fully twelve feet over all. However, the spider crabs 
are less remarkable for their size than for the curious 
habit they have of masking themselves with plants and 
other growths. Sluggish and apparently stupid in their 
ordinary habits, in this one instance they surpass all 
other crustaceans in the display of reason : they will 
purposely select certain seaweeds, hydroids, and other 



72 Dwellers of the Sea and Shore 

organisms and affix them to the hairy hooks on their 
backs, ostensibly for the purpose of concealment. Their 
show of intelligence in choosing only those materials 
that will bear transplanting and with reference to their 
colors has long occupied the curiosity of the lay person 
and the serious attention of the naturalist. 

The spider crabs being vegetarian in their habits, it 
is quite evident that their presence among the mussels 
is a peaceable one; they frequent the beds to feed on a 
variety of small seaweed that grows on the shells. But 
the mussels are, nevertheless, the victims of nocturnal 
raiders not far removed in kind from the spider crabs. 
These are the sand crabs {Cancer irroratns) who. with 
their powerful claws crumble away the margins of the 
valves, thus gaining an entrance to the occupants 
within. In these marauding exploits they are well 
attended by a tribe of smaller fry, the hermit crabs, 
which warily await just out of reach of the dangerous 
forceps until the owners have finished eating, when 
they at once pounce upon the fragments which the sand 
crabs have disdained to consume. Sometimes it hap- 
pens that a hungry hermit crab in its eagerness or 
impatience approaches too near the formidable diner. 
Instantly it is seized and in spite of its attempt to 
retract as far as possible into its borrowed shell, this 
is broken away and the unfortunate inmate is plucked 
out piecemeal and leisurely devoured. 

It must not be assumed, however, that the shocking 
exhibitions of ruthlessness are the sole reward for one's 
pains to visit the beach in the night; there are other 
compensations that go far to eliminate the unpleasant- 
ness of these contacts. Outstanding among these, with- 



The Comb Jellies and Others 



73 



oat a doubt, is the display of phosphorescent light by 
the various animals of the sea and shore. Especially 
striking is this phenomenon on a clear summer night 
before the rising of the moon. Here and there, among 
the pebbles and swarming over the swaying seaweeds, 
can be seen tiny points of bluish light; pale floating 
clusters of liquid fire are carried to the shore by the 




bolina; a phosphorescent comb jelly, (photograph taken in the WATER. "> 



waves to break upon the sand with a brilliant sheen; 
even as one walks, one's footsteps mark a softly shim- 
mering trail, in which the quivering glow lingers for a 
while, hesitates, and then dies out. 

These lights are variously emitted by minute 
crustaceans, comb jellies and worms. But by rea- 
son of the larger volume of light given oft by each 
individual, and on account of their enormous numbers, 



74 Dwellers of the Sea and Shore 

the comb jellies arfc far more conspicuous than the 
others. 

The comb jellies, or Ctenophora, exist in every 
ocean. They are nearly as abundant in the arctic as in 
the temperate and the tropical waters. Of the several 
hundred different species which make up this group, 
perhaps less than a half dozen are known to other per- 
sons than professed naturalists. Even these few 
would doubtless have escaped common observation 
were it not for the extraordinary play of prismatic 
colors that is reflected from their bodies in the sun- 
light; for otherwise, because of their great transpar- 
ency, they are practically invisible. 

One particularly common comb jelly is the exquisitely 
beautiful "rainbow jelly" (Mnemiopsis leidyi) which 
makes its appearance on our Eastern coast during the 
hottest season of the year. In general form it is pear- 
shaped, somewhat flattened on two sides. Specimens 
six inches in length are not uncommon, but the great 
majority are more nearly four inches. Whenever one 
of these delicate creatures is encountered, others are 
almost certain to be in the immediate vicinity; they are 
gregarious — that is, they collect together and wander 
about by thousands. Although not a rapid swimmer 
it is a graceful one. It progresses with an undulating 
motion by means of eight rows of flat hairlike processes, 
or cilia, arranged in meridianal lines over the surface. 
The filmy gelatinous character of its body substance 
makes it extremely difficult to handle, and it cannot be 
lifted from the water without injury; yet, in spite of its 
delicate structure, it captures small fishes and crus- 
taceans for its food, and has been known to devour 



The Comb Jellies and Others 



IS 



other comb jellies as large as itself. Exceedingly phos- 
phorescent, its brilliant green light flashing intermit- 
tently in the night time makes a spectacle in the waters 
that is singularly entrancing. 

Another ctenophore, less often seen, though common 
enough at times along the shores of New England, is 
the u comet jelly" {Pleurobrachia rhododactxla) , an 




pleurobrachia; the comet jelly. 



iridescent bubble of pink of about an inch or more in 
diameter. This little living transparent sphere courses 
its way here and there through the water, sometimes 
with a revolving and sometimes with a rotating motion 
effected by the paddling of its eight rows of cilia. But, 
more often than not, a curious exhibition accompanies 
these active movements. From what appears to be two 
nodes, the size of a pin's head, situated on opposite 
sides of the sphere, there will be extended and retracted, 
suddenly or gradually, as the case may be, a pair of 
threadlike streamers fringed along one side for their 
whole length with long waving cilia. As these slender 



y6 Dwellers of the Sea and Shore 

and gauzy plumes elongate, they trail behind the swim- 
ming animal in graceful undulating curves until they 
reach the amazing length of twenty or more times the 
diameter of the body. 

At one pole of its body is the mouth, a narrow, slit- 
like opening; at the other is a small area in the center 
of which is the so-called "eyespot." This eye, however, 
cannot see as the fullest meaning of the word would 
imply, being sensitive only to light and darkness. Yet, 
notwithstanding, it seems to be aware of the approach 
of danger, for often the presence of a moving boat or 
other commotion in its neighborhood will cause it to 
disappear toward the bottom. 

Now it will be noted that in the two forms just 
reviewed, the motor appendages, or cilia, by means of 
which they swim, are arranged in eight rows. In all 
ctenophores these rows run in a direction with the longi- 
tudinal axis of the body, and it is from their fancied 
resemblance to combs that the early observers assigned 
to the members of the entire class the term u comb 
jellies" ; hence, their systematic name Ctenophora, or 
comb bearers. But, although the comb jellies are easily 
recognizable by virtue of their swimming organs, this 
distinction is, after all, a very superficial one. They 
are classed apart from the true jellyfishes, or Scyphozoa, 
because of other very real and far more fundamental 
differences. Besides the fact that both sexes are united 
in one individual, the comb jellies may be said to differ 
from the jellyfishes chiefly in their method of reproduc- 
tion, which is to say, their eggs hatch directly into free- 
swimming young who in appearance or habits are in no 
essential respect unlike the adults, That this is not so 



The Comb Jellies and Others 



11 



in the case of jellyfishes, will be made clear in what 
follows. 

The large jellyfishes, or medusae, as they are also 
called because of their tentacles which are suggestive 
of the Gorgon's locks, range from the size of a mere 
speck to several feet in diameter. But however di- 
verse may be their dimensions, they all agree in general 




pelagia; a jellyfish. 



outlines and plan of structure. They are umbrella- 
shaped, or, rather, they are roughly comparable to a 
mushroom in which the stalk is superseded by depend- 
ent central organs, the mouth and stomach of the ani- 
mal. As in the case of the comb jellies, many of the 
jellyfishes are phosphorescent; some are luminous over 
the entire body, others have light-producing organs of 
a more restricted type; and, also, like the ctenophores, 
they inhabit all seas. 



78 



Dwellers of the Sea 



In Hempstead Harbor two striking and uncommonly 
beautiful forms make their appearance regularly in the 
middle of May in each year. These are Aurelia flavi- 
dula and Cyanea fulva; and they sometimes occur in 
such enormous shoals that one has difficulty in making 
his way with a boat lest his oars strike them and muti- 
late their beautiful bodies. Storms sweeping in from 
the Sound with unwonted violence will occasionally 



the margin of t! 


^i^^"1f¥^fftes*yJ tin- n 


tmilics allied i 


ij tentacles andJB 


P^H^ " ! -^ite 


li surrounded 


■ive appenilaij«U!ii 
fides, awl dR^ 


' >*y 


fctoma are de 
BfcJ along the 


only a ^9HSH 


JjjwPn j . i — .1 _•■ -1W|wi| 


Hkof the ! 


<listmdBaMMB 


Bi'tuug thi Diseophftfc^ ' 


BB»i woui 




pTe.^F.B and I)iscoriicuu: a 
vhieh 1 wouU eaP DiseJ^^H 


~*f and t 

|HHpX)ME.'K, 


iklaj SJSP- i| 


u;i'l;v A comparison olSpi 


;-r*^ v.-;!i 


;eh th«fl|BP 


I <hey have geuerdJ; 

fctheiu. Instead ■>£ s ' ; -<4f^^H 


' u!;;" 


with ^mH| 


*** 


^•Ue, ,o t 


Ephy ra>, 1h9BS| 


^^^HP^f -tiiiBP * 


5j»g to form. 


aistakable. ^HH5 




(^production 


agree in their oral 


. 


e SemseostonW 


undergo a dired 


•flit inten 


.•ruin- »trobifc 



DISK OF A DRIED JELLYFISH. A TRANSPARENT FILM THROUGH WHICH TYPE EASILY 
CAN BE READ, IS ALL THAT REMAINS AFTER EXPOSURE TO THE SUN AND AIR. 



throw them up on the beaches in masses, where ex- 
posure to the sun reduces them in a short time to an 
almost invisible film. This almost total obliteration by 
the sun is due to the relatively small actual body sub- 
stance that constitutes the jellyfish; for despite their 
large bulk, they are slightly less than one hundred per 
cent water. 

Aurelia, when full grown, is about ten inches in 
diameter. Its broad, transparent disk is somewhat like 



The Comb Jellies and Others 79 

a crystal dinner plate indented at the margin with eight 
notches. In each of these marginal notches, hidden by 
a hood, is a small tubercle containing the eyespot. A 
very short cluster of tentacles fringes the circumference 
of the animal. Four horseshoe-shaped sex organs ar- 
ranged in a geometrical pattern around the center, well 
within the body, are a conspicuous and ornamental fea- 
ture. By their color, one can readily recognize the sex 
of the individual: in the male they are pink, and in the 
female they are yellow. Aurelia revels in the sunlight. 
On cloudless days, when the water is smooth, it swims 
near the surface, reflecting the most delicate hues im- 
aginable from its purple-tinged tissues. 

In common with other jellyfishes, Aurelia swims in 
a very characteristic manner. Not being possessed of 
swimming paddles, or cilia, like the comb jellies, its 
mode of progression, quite obviously, differs from 
theirs. In short, it propels itself, not by the aid of 
organs adapted to this purpose, but by alternately con- 
tracting and expanding its disk. The action is like 
nothing so much as the partial closing and opening of 
an umbrella. This jellyfish never rests. The rhythmic 
movement of its body continues without intermission 
throughout its adult life like the beating of the human 
heart. 

No less remarkable for its beauty is Cyanea fulva. 
This species may well be termed the "little brown 
brother" of the more widely known C. arctica, or sea 
blubber, the largest jellyfish in existence. Although 
more local in its distribution than the latter, and dif- 
fering from it in size and color, its general appearance 
and habits are otherwise about the same. In our 



80 Dwellers of the Sea and Shore 

Cyanea the disk is seldom larger than that of Aurelia's, 
but is more domelike; the incisions of the margin are 
more pronounced and are sixteen in number; only eight 
of these notches, however, contain eyespots. On the 
under surface is the central mouth, surrounded and hid- 
den by four long voluminous veils that hang in loose 
folds. Near the margin, separated into eight distinct 
clusters, are the tentacles. 

Here we come to what are perhaps the most singular 
organs in the animal kingdom. For one who sees our 
Cyanea the first time, as it floats serenely near the sur- 
face, trailing beneath its pulsating body these long and 
multitudinous threads, some of which are spun out for 
several feet and glisten like the finest gossamer, it is 
hard to realize that the jellyfish is anything but defense- 
less. But let one inadvertently expose his bare skin to 
the touch of the delicate strands and he will quickly 
withdraw with surprise. And if the specimen encoun- 
tered be large enough, his surprise will not be unmin- 
gled with pain. The tentacles are, in fact, the crea- 
ture's stinging organs wherewith it shocks and benumbs 
its prey. With these formidable weapons it literally 
combs the water for small fishes, crustaceans, and other 
animals upon which it feeds. They are contractile and 
extensible; indeed, the enormous length to which they 
can be extruded gives a considerable compass to the 
operations of the animal. But it so happens that 
Cyanea is not always hungry. Nevertheless, any luck- 
less swimmer that grazes the paralyzing snare is seized 
and stunned just the same. It is soon released, how- 
ever, and sinks to the bottom as if dead. Then, after 
a while, the effect of the shock seems to pass off, the 



The Comb Jellies and Others 81 

animal recovers, and swims away apparently no worse 
for the experience. 

This remarkable capacity of the tentacles, wherewith 
the jellyfish is enabled to subdue its prey by stunning it, 
is due to hundreds of minute stinging cells that invest 
those organs. The cells are somewhat egg-shaped, 
with thickened elastic walls, and each one contains a 
coiled threadlike filament, one end of which is attached 
to the cell. The free end is pointed (in the case of 
some organisms it is barbed, in addition) and is charged 
with a highly irritant poison (believed to be formic 
acid). When organic matter, such as food animals or 
other edible material — for the jellyfish eats both the 
living and the dead — comes into contact with the ten- 
tacles, the cells in the immediate vicinity of the col- 
lision become excited and burst with such force that the 
poisonous filaments are driven into the object. It is 
to the noxious property of these myriads of poisonous 
darts that the paralyzing shock is due. 

As I have already implied, the sexes are separate in 
the jellyfishes. The spawning season of Aurelia and 
Cyanea, which takes place in midsummer, is often 
marked by inordinately thick shoals of the congregating 
males and females. The eggs are carried in the ma- 
ternal pouches until they have developed into little 
pear-shaped bodies (planula) covered with short cilia 
enabling them to swim. When they are liberated they 
wander around for a short time, but finally find their 
way to the bottom where they attach themselves to 
plants and stones. Then begins a series of marvelous 
changes in the growth and development pi the jellyfish. 

In attaching itself, the embryo does so on the narrow 



iSdSi 



82 Dwellers of the Sea and Shore 

end of its body. At the opposite, or free, end is the 
mouth, around which some little tentacles, usually six- 
teen, soon make their appearance. These latter are 
armed with stinging cells, the extruded threads of which 
give them a bristled appearance. It now commences 
to take food, and, consequently, begins to grow; but it 
will be some time before its details can be seen without 
the aid of a very strong lens. This is known technically 
as the scyphostoma stage. 

As the scyphostoma grows, it lengthens considerably. 
At the same time an encircling constriction begins to 
make its appearance just below the base of the tentacles. 
Then gradually others appear in succession at regular 
intervals down the whole length of the animal. Finally, 
so deep do they become that the little jellyfish is seg- 
mented and now looks like a miniature stack of shallow 
dishes. But in the meantime another change takes 
place. The topmost, and first-formed, segment loses its 
tentacles, and the margin becomes deeply indented. 
The remaining segments then in turn develop similar 
indentations on their circumference, and the w T hole now 
assumes a decided plantlike appearance. This later 
form that these transformations have wrought is called 
the strobila. 

The number of segments, or, more properly, disks, 
on a single strobila may reach as high as thirteen or 
more, but generally the total is less. The constriction 
separating the uppermost disk eventually becomes com- 
plete, and the liberated part, called an ephyrula, inverts 
itself and swims away. In a short time it grow r s ten- 
tacles, and becomes a perfect, though tiny, jellyfish less 
than an eighth of an inch in diameter. Following the 



The Comb Jellies and Others 



83 



departure of the first ephyrula, the others soon detach 
themselves to pursue their individual ways. They will 
continue to grow, and in their turn produce eggs, until 
six months later, when their cycle of life is complete, 
the autumnal storms will have brought about their 
death and disintegration. 




STROBILA OF AURELIA. 



Regardless of their common name, "jellyfishes" are 
not, in any sense of the word, fishes. They, together 
with comb jellies, belong to a very different and far 
lower phylum known as the Ccvlenterata, a division of 
the animal kingdom that includes also the plantlike 
hydroids, the anemones, and the corals. Xor must it 
be inferred that all jellyfishes develop in exactly the 
same way as Aurelia or Cyanea. Some there are which 



84 Dwellers of the Sea and Shore 

start out in life as a spherical swimming egg, called a 
planula, and later become branching hydroid colonies; 
in other species, neither the colonial nor the strobila 
stage marks their metamorphosis; they pass without 
alternation of generation directly into the ephyrula 
state. 

Notwithstanding that many of the comb jellies and 
jellyfishes are luminous, they are not essentially crea- 
tures of the night. It is true that some species among 
the latter never liberate their eggs until after the sun 
has set; however, it is equally certain their eating habits 
are not regulated by the sidereal alternation of daylight 
and darkness. Yet it is the night that reveals them in 
their most peculiar splendor. If by day the witchery 
of these resplendent forms is overwhelming, what shall 
we think of them at night when the fulgor of their mys- 
terious lanterns flashes forth in the inky depths like 
pale-blue comets or streaks past with the similitude of 
shooting stars in the moving tide? 

In general it may be said that little is known about 
the nature of animal light, and the luminous property 
of coelenterates in particular is still an obscure subject. 
Indeed, even the life histories of only a few jellyfishes 
themselves are completely understood. One who would 
aspire to explore in a most interesting and an undevel- 
oped field cannot do better than to give his attention 
to the coelenterates, a group whose members easily rank 
among the most beautiful of all the living wonders. 



Chapter VI 
SOME FRIENDS IN ARMOR 

If it so happens that the tide is favorable, the early 
light of an August dawn not infrequently finds me rest- 
ing athwart the stern of my little boat, idly drifting in 
the shallow waters close to the harbor shore. Here 
the placidity of the sea, the companionable cries of the 
breakfast-hunting crows and gulls circling above the 
beach, the cool morning air dissolving the rising mists 
that hover along the cove, conspire to give an ardent 
glow to the enthusiasm with which I pursue my am- 
bitious quest. For on the present occasion whereof 
I write, my early morning adventure has a more definite 
object than that of general observation. 

Still, the familiar, pleasing details of the scene do not 
escape me regardless of the smaller compass that re- 
quires my attention. Even the sea seems now to be in 
its most delightful mood. Later, when the full heat 
of the day sets in, my motionless, open boat exposed 
to the direct rays of the seething sun becomes a veri- 
table griddle; but in the present propitious hour, the 
temperature stirs the blood. And as I gaze into that 
wonderland over which I float, its serene and refresh- 
ing aspect quickens my very perceptions. 

Among the water grasses and swaying seaweeds, I 

85 



86 Dwellers of the Sea and Shore 

catch the flutter of a flatfish as it makes its low leap 
across the rippled sand. The starfish, the moon snail, 
and the comb jelly, too, hold forth in the watery haunts ; 
and there comes and goes a host of others. 

Nearer is a pebbled area barren of vegetation. Here 
among the mussel clumps an occasional oyster can be 
seen with gaping valves competing with its neighbors 
for the microscopic harvest of the water. Almost with- 
in reach of my hand a low, sinuous mound slowly ex- 
tends its length. The mole of the land has its rep- 
resentative in the sea. This tortuous trail is formed by 
the labor of the young horseshoe crab. Resting on the 
bottom, which it simulates with astonishing realism, is 
a squid. Unintimidated by my immobile presence, it 
watches with its great lugubrious eyes the approach of 
a shoal of killifishes. The minnows move in rhythmic 
progression, casting a stippled shadow over the 
gravelly floor, unaware of the danger that lurks beneath 
them. For an instant they hesitate — too late ! The 
weird apparition suddenly darts into their midst, 
dispersing them in all directions; but not before 
it has seized several stragglers in its terrible arms. 
With a vicious snap of its beak, it speedily exterminates 
them. Not content with one victim, which would be 
fully ample for its meal, the monster ruthlessly de- 
stroys what cannot possibly serve its needs. 

What manner of instinct is this that gives such scant 
consideration to the conservation of life, an instinct the 
primary impulse of which is an extravagant lust for 
killing? For a moment, forgetting the dictum of 
nature which properly holds that many must die so one 
may live, forgetting that awful equilibrium in which 



Some Friends in Armor 87 

there is maintained a just proportion of life through 
the ferocious but necessary medium of the stomach, and 
forgetting that here is but an operation of a benevolent 
law which determines the survival of the devourer to be 
in direct dependence on the unfitness of the devoured, 
I look upon this rapacious butchery with horror. 

A dreadful fascination holds me, and with rapidly 
beating pulse I lean far over the rail. The movement, 
however, betrays my presence, and the animal on per- 
ceiving me takes alarm and slinks away, leaving in its 
trail an inky cloud. 

My attention is now drawn toward a spot near by 
a small clump of mussels, where in the uncertain haze 
caused by the retreating squid I catch now and then the 
fleeting glimpse of the agitated movements of a young 
moon snail's shell. At once I recognize the object of 
my early visit to the seashore. It is the little hermit 
crab (Pagiirns longicarpas) . 

Here he comes, now ! Crawling actively over the 
bottom, he pauses from time to time and scrapes the 
sand in search of a morsel of food. From his busy 
claws comes the glint of the morning sunshine, and on 
the texture of those members there is a delicate iri- 
descence produced by the diffraction of light. Soon he 
spies a dilapidated whelk shell half buried in the silt, 
and cautiously advances toward it. Its size is nearly 
equal to the one he carries; its decrepit condition, its 
calcareous incrustations, to which small seaweeds have 
anchored themselves, show that several summers have 
passed since it was instinct with life. After a prelim- 
inary frisk with his long threadlike feelers, he quickly 
rolls it over several times, giving the exterior a rapid, 



88 Dwellers of the Sea and Shore 

but thorough, examination. Then deftly inserting his 
great claw into the opening, he explores the interior. 
A scale worm, clinging just within the glazed en- 
trance, seems evidently not to concern him. The crab's 
pressing occupation now is to determine whether or not 
these precincts contain something more formidable — 
perhaps a member of his own tribe. He finds it free 
from these, however, and prepares to take it over. 
Grasping the rim with his pincers he is about to with- 




polynoe; the scale worm. 



draw from his old shell and transfer to the new-found 
one when his antennae fall across the worm. This 
causes him to hesitate. Oh, well; no matter. There 
seems to be room enough for two. So, without more 
delay, he vaults over swiftly and nimbly into the other 
shell. 

Possession is followed immediately by a momentary 
disappearance whereupon all but the tips of his claws 
are hidden from sight. Soon his fore body emerges, 
and by the aid of the currents that wash the gill cav- 
ities, he sends forth a stream of particles consisting of 
the sand and debris that have filtered into the recesses 
of the scurfy ruin. The operation of retreating into 



Some Friends in Armor 89 

the interior and coming forth to eject the rubbish is 
repeated several times, during which he does con- 
siderable squirming in the effort to adjust himself to 
the convolutions of the shell. 

After these precautions against insanitation and dis- 
comfort, the crab, with his flexible hind body firmly 
wrapped around the columella, or inside spiral, extends 
his legs and walks alertly away. 

Now, in the strict sense of the word, the hermit crab 
is neither a hermit nor is he a crab. One may forgive 
the original nomenclators for misnaming this animal; 
in their rude system everything that carried claws was 
called a "crab." But the fact that they have bequeathed 
to posterity the misleading appellation of "hermit" is 
entitled to scant courtesy. Indeed, the fancied resem- 
blance of the shell of the hermit crab to the shelter of 
a hermit is no more analogous than that the shirt on 
one's back is one's home. Nor is he averse to the com- 
pany of his fellows. At no time does he lead a life of 
seclusion. Furthermore, among other of his un-hermit- 
like attributes, as we shall have occasion to discover 
later, is his fondness for female society in particular. 
Yet this instance is a trifle to some of the blunders of 
popular nomenclature ; therefore, I shall pass it without 
further comment, lest I be accused of weighing hairs. 

But his claim to membership among the crabs, hang- 
ing as it does by a still more slender thread, is a seri- 
ous matter, and cannot be dismissed so easily. The two 
great groups into which the higher crustaceans are sep- 
arated bear the scientific names of Macrura and Bra- 
chyt&a; meaning, respectively, "long-bellied" and 
"short-bellied." Of those crustaceans who are mem- 



90 Dwellers of the Sea and Shore 

bers of the suborder Macrura, the lobster and the well- 
known fresh-water crayfish can be cited as the most 
familiar types. The distinguishing feature that places 
them in this division is, as the name implies, the pos- 
session of a long cylindrical abdomen, or hind body. 

To the Br achy ur a only, belong the true crabs. And 
these are distinguished by the inconspicuous flat hind 
body reflexed along the under side of the thorax, or 
fore body. A common example of this division is the 
edible, or blue, crab of our tables. 

These distinctions, by the way, are not arbitrary 
arrangements made merely to suit the convenience of 
the systematic scientists; for the most superficial ac- 
quaintance with comparative anatomy soon reveals that 
the crablike animal differs more greatly from the 
lobsterlike individual than does the dog from the cat. 
It is therefore because of this anatomical, or, to use a 
more correct term, this morphological difference that 
the hermit crab is incontestably removed from the 
brachyurians, or crabs. 

However, regardless of those general features of his 
hind body that cause him to be set apart from the crabs, 
he is by reason of a striking modification of the form 
and function of this part of his anatomy peculiarly dis- 
tinguished from all other creatures of his kind. Indeed, 
it is on this account that some writers have relegated 
him to a distinct group of his own, know T n by the name 
of Anomura, the u nameless bellied" ; for his unusual 
hind body not only makes him notorious among crus- 
taceans but places him among the curiosities of nature. 

Unlike the fore body and its appendages, which are 
armored with a hard, tough crust, the abdominal region 



Some Friends in Armor 



91 



of die hermit crab is soft, weak, and defenseless; it is 
invested with a thin membranous cuticle of a texture 
so delicate that the slightest abrasion will rupture it; 
an injury to this tissue is almost sure to prove fatal. 




MALE HERMIT CRAB REMOVED FROM HIS SHELL; SHOWING THE SOFT UNARMORED 

HIND BODY. 



Beginning at the very slender waistline, the bulging 
paunch assumes a spiral form and tapers toward the 
tail, where it is terminated by an aborted caudal fan, 
the use of which assists the crab in maintaining a grip 
on his borrowed shell. It is here that the intestinal 



92 Dwellers of the Sea and Shore 

tract ends. Two other appendages are found on the 
left side, and a glance at their location and structure 
leaves no doubt of their origin. They are vestiges of 
what were once highly specialized locomotor append- 
ages in the ancestral form of this animal. But now 
these degenerated, feeble, bristle-fringed outgrowths 
serve an entirely different purpose. In the case of the 
male crab their chief use is for sweeping forward the 
stercoraceous matter deposited in the shell; in that of 
the female they serve the additional function of anchor- 
ages for her extruded eggs. 

The only effective strength that the hermit crab is 
capable of exerting to secure himself in his shell is con- 
centrated in a small group of muscles extending along 
the under side of the hind body, and it is for the pur- 
pose of retaining this hold that this region has acquired 
its remarkable formation. In short, his belly functions 
as an organ of prehension; that is to say, a grasping 
organ. 

It is apparent from the foregoing that the crab is 
not only compelled for reasons of safety to adopt a 
defensive covering, but when changing from one shell 
to another he also must act with the utmost dispatch 
if he is to avoid being seized by some predatory rover 
who may be near. Still, although it may be with good 
reason that the exchange is made quickly, it must be 
said that ofttimes it appears utterly without reason 
that the exchange is made at all. Now many motives, 
real or fancied, may inspire him to leave one shell for 
another, but there is only one distinct physical cause 
that absolutely forces him to seek a new covering. This 
cause arises from the simple fact that the crab grows. 



Some Friends in Armor 93 

The hermit crab lives long, indeed, if he survives the 
attacks of enemies and the dangers of parasitism for 
four summers' duration; but seldom does his life bear 
so extraordinary a charm. During the earlier part of 
this period he molts at least once — and sometimes, 
though rarely, twice — a year. Each molt is accom- 
panied by an increase in size; and as a consequence he 
is obliged to find a larger shell. This shell needs never 
to be wanting for long. He has but to choose almost 
at random from the abundant supply around him, to 
find one suitably roomy. Yet times innumerable have 
I witnessed the abandonment of one for another, and 
for no apparent purpose other than to satisfy a 
crotchet. Moreover, he is not overscrupulous in the 
selection he finally does make. With so many to choose 
from, it would appear that instinct, if not reason, would 
determine the proper choice and impel him to select 
only that kind best fitted for his comfort and protection. 
He will, nevertheless, abandon a specimen which for 
convenience and capacity leaves nothing to be desired, 
and wedge himself into another so small that there is 
scarcely space enough to retract his fore body in time 
of extreme danger; in truth, he will adopt with equal 
facility the covering of a perfect shell or a fragmentary 
portion that passes as such. 

Few instincts are more strongly developed than the 
instinct of self-preservation; in the crab, however, this 
instinct, exemplified by his preferences for protective 
coverings, shows some strange aberrations. I have 
found him encased in crumbling shells of rotten chalk, 
in a piece of spongy bone, in a bent ferrule from a 
jointed fishing pole, in a cumbersome hollow stone, in 



94 Dwellers of the Sea and Shore 

a broken bottle neck and, more than once, in a remnant 
of a crushed shell which being little more than a girdle 
left his hind body as exposed as his head. Needless to 
say, his investiture with these heterogeneous materials 
reduces his capacity for defense, and exposes him to 
perils ordinarily improbable were he to provide himself 
with a more efficient form of protection. Could there 
be a more utter want in the display of intelligence? Oh, 




HERMIT CRAB IN A BROKEN SHELL. THE DISINTEGRATING SHELLS THEY SOME- 
TIMES USE LEAVE PORTIONS OF THEIR BODIES EXPOSED TO THE ATTACK OF 
ENEMIES. 

for only a ray of reason ! The faintest gleam would 
advance his welfare more in one brief moment than for 
him perpetually to grope in the darkness of aborted 
instinct. 

Let us return to our wanderer. Having ensconced 
himself in his recently acquired shell, he now leaves the 
scene of the transfer in considerable haste. The truth 
is, his movements betray an unwonted agitation. His 
antennae jerk spasmodically, and his nimble crawl ac- 



Some Friends in Armor 95 

celerates to a brisk run. It is evident that some singu- 
lar attraction in the vicinity draws him onward. Ah, so 
that is it! I suspected as much. He has come upon 
the partially devoured carcass of a female sand crab, 
over and around which the mud snails {Nassa obsoleta, 
Nassa trivittata) and other small scavengers are 
swarming. The crushed carapace of the animal shows 
that it met its death under the spiteful heel of some 
fisherman, a stupid clown who, prompted by innate 
wantonness as well as by a desire to safeguard his lines 
from a bait pilferer, has in this ignorant act destroyed 
one of his most valuable assets; for the larval young of 
these creatures serve as the chief supply of food to 
many fishes. 

Arriving at the table the hermit crab brushes aside 
several of the assembled diners, and with his great 
claw tears from the exposed flesh a choice portion 
which he retains in this member; then using his smaller 
claw he plucks from the detached piece shred after 
shred which he carries to his mouth. Daintily, deftly he 
performs this gastronomical feat with a fastidiousness 
almost humanlike; but notwithstanding this apparent 
refinement, the crab, like all animals which live pre- 
cariously, gorges to surfeit. With but few exceptions 
the search for food among the denizens of the seashore 
entails an acute problem, a problem wherein the strug- 
gle to eat is surpassed in intensity only by the struggle 
to keep from being eaten. And, curiously, it is with the 
higher forms that this struggle to maintain life is the 
most bitter. The tiniest morsel has scores of competi- 
tors. When, through accident or otherwise, a death 
among one of the larger animals takes place, a veritable 



g6 Dwellers of the Sea and Shore 

windfall occurs; and the event seems to be telegraphed 
to the legions of the sea. Myriads hasten to the ban- 
quet. One and all, they come : the snails, the worms, 
the crustaceans. All, within the radius of the effluvial 
currents hurry to dispose of the corpse. Thus, in the 
economy of nature, each individual plays a part of the 
utmost importance; for it is through the desperate 
agency of hunger that the waters of our shores are 
purified. 

After reducing the portion which he holds in his big 
pincer to a size small enough to be manipulated by the 
pair of fingerlike clasping appendages near his mouth, 
he passes to these what is left, and decides to move on. 
He does not proceed more than a few feet, however, 
before he stops and devotes some time in consuming 
what he can of the rest of his food; but, as he has 
literally bitten off more than he can chew, he finally 
ends by rejecting the remainder altogether. 

Having satisfied the inner man, the hermit crab now 
gives some consideration to his external needs; for he 
is more or less of a fop, and will sometimes spend 
hours in grooming himself. Using either claw with 
equal facility, he rubs and scraps all parts of his fore 
body and its appendages. His time, however, is given 
mostly to the cleaning of his feelers, his eyestalks, and 
his legs, whereof the joint of the last named receive 
particular attention. Moreover, these toilet functions 
are very necessary; were he to neglect them in the 
slightest detail, his crust would eventually be overrun 
with plant growths which find in the horny composition 
an admirable holdfast; and their presence would in- 
directly cause his premature death by impeding his 



So?ne Friends in Armor 97 

movements and making it difficult — in fact, impossible 
— successfully to cope with the vicissitudes of a life that 
is hazardous at best. The result of this neglect is evi- 
dent in the case of old crabs, many of whom, no longer 
retaining the suppleness of youth, have tufts of seaweed 
growing in those areas inaccessible to their chelipeds. 

Hello! Who is this? Another hermit crab, at- 
tracted by the feast that our friend just left, has come 
within several inches of the primper. He is a great 
hulk of a fellow; and his shell is covered with a downy 
growth, for he carries with him a colony of caelenterates 
(Clava leptostyla) , which makes him look for all the 
world like a giant clad in furs. 

Each catches sight of the other at the same instant. 
A momentary pause ensues. Then each, with his great 
claw extended, makes a sudden and furious rush for the 
other. The clash and rattle of their shells on the 
pebbles can be heard distinctly through the water as 
they come to grips and wildly seek an advantageous 
hold. Jabbing, cuffing, wrestling, they display an aston- 
ishing agility, encumbered as they are with their heavy 
shells, and the rapidity of their movements behooves 
one to watch sharply if he is to observe every detail. 
Now one is uppermost, now the other. Separating, 
they encircle one another with a sidewise movement, all 
the while keeping their big pincers thrust forward. 
Again they come together. They part. This time, 
however, the newcomer betrays a craven spirit; he pre- 
cipitately leaves the field with a backward run. It were 
better, perhaps, to say he attempts to leave, for in his 
rapid retreat a stone obstructs his way, and the impact 
sends him topsy-turvy, causing him from fright or sur- 



98 Dwellers of the Sea and Shore 

prise to withdraw completely into his shell and to block 
the entrance with his claws. In a trice the other is upon 
him. Seizing one of the exposed claws, he tries to dis- 
lodge him by tugging so violently and rapidly that the 
collision of their shells beats a tattoo. The persistent 
attack evidently arouses a spark of pugnacity in the 
poltroon, for he relaxes sufficiently to emerge and flour- 
ish a threatening pincer. This, however, is his undoing. 
He is immediately grasped by one of his rear legs, is 
jerked clear of his shell, and is tossed over the aggres- 
sor's shoulder. 

The vanquished crab, now exposed in all his naked- 
ness, curls his hind body under him and gropes around 
excitedly for some sort of object that will afford a 
shelter. None is within sight. It is now u any port in 
a storm. " So, thrusting his hind body into an interstice 
among the pebbles, he assumes a defensive posture and 
keeps a wary eye on the victor who, meanwhile, follow- 
ing the unvarying procedure among his kind, is feeling 
around the inside of the empty shell with his formidable 
claw. After a momentary investigation he exchanges 
it for the one he carries. Obviously all is not satis- 
factory; in a very short time he returns to his own. 
Now, according to the rules of fair play, he should at 
least be generous enough to relinquish the spurned shell 
to the loser, as he can by no means avail himself of the 
spoils of the conquest and still retain the shell he bears. 
But fair play is no part of the hermit crab's code of 
ethics; therefore, he seeks to distrain the other who 
soon shows a disposition to press matters in order to 
regain his property. 

Awaiting in vain for an incautious moment when the 



Some Friends in Armor 



99 




loo Dwellers of the Sea and Shore 

victorious adversary would relax his vigilance, the dis- 
possessed crab ventures closer. When within a few 
inches of the guarded shell, he makes a bold attempt 
to feint his enemy from his position by making a quick 
circuit around him at close quarters. The other is not 
to be caught napping, however. He engages the bereft 
one, and with a well-directed cuff, sends him flying 
backward. 

These maneuvers are repeated again and again until 
it w T ould seem there is no ending, or until one of the 
two tired of the contest, were it not for a circumstance 
that makes both of them forget their private quarrel. 
Two other males arrive in the vicinity. The first to 
spy them is our gladiator. He hurries forth to meet 
them, leaving behind the disputed shell. Then follows 
a skirmishing fight in which three hermit crabs are 
engaged. 

This is an opportunity not to be lost by the defense- 
less one, so he speedily takes possession of his chattel. 
One would imagine that from his recent experience he 
has had his fill of fighting. Not so, however; he 
hastens to the fray and takes his part quite lustily, and 
the affair now becomes a battle royal between all four. 
For a number of seconds there is a confusing tangle of 
brandished claws and animated shells, while the stac- 
cato clicking of the latter rises in crescendo. Sud- 
denly one of the warriors is knocked sprawling, upon 
which event the mass with one accord disintegrates and 
the crabs depart, all going their several ways. The 
fracas is over as suddenly as it was precipitated. 

Let me here observe that of the hundred brawls I 
have witnessed between hermit crabs — in none of 



Some Friends in Armor 101 

which, by the way, have I ever seen an individual suffer 
a serious bodily injury — all were repeated without es- 
sential variation from the foregoing incident. Please 
note, however, that there is always a violent exertion 
on the part of the aggressor to dislodge the other, and 
when this is effected it is seemingly brought about by 
a tug that jerks the defeated crab clear of his shell. 

That this exhibition of force is more apparent than 
genuine, I shall try to make clear by a brief analysis. 
If, with my fingers, I attempt to extract a hermit crab 
from his shell, one of two things is bound to happen. 
He either will throw off his claw or other appendage 
which is under tension, or he will suffer his body to part 
in twain. In the first instance, provided it is a cheliped 
or walking leg only that is concerned, the damage, par- 
ticularly in the case of the younger animals, will be 
compensated for by the growth, or regeneration, of a 
new member at a succeeding molt. In the latter in- 
stance it is a graver matter, as the sundering of a vital 
organ results in almost instant death. Try as I can, 
however, it is impossible to remove the crab without 
recourse to methods less violent and of an entirely 
different nature. 

Now no hermit crab is strong enough to dismember 
his antagonist, much less pull him apart. It therefore 
follows that even the largest and most powerful of 
these animals — whose strength, of course, can not ap- 
proach that of my fingers — are utterly incapable of 
drawing an opponent from his shell by sheer force. 

But, granting that the crab's strength is equal to the 
attempt, it is plain in the case of evenly matched indi- 
viduals that the aggressor is as likely to wrench his 



102 Dwellers of the Sea and Shore 

own limb from his body as to inflict this injury on his 
adversary. 

Nor should the strenuous muscularity displayed by 
the crab be accepted without question. I have seen, 
times without number, this same agitated and frantic 
attack made upon empty shells, the same tugging and 
straining of forelegs inserted into a vacant interior, the 
polished nacreous walls of which could offer no possible 
resistance. 

What is it, then, that causes the crab to leave a 
shell that he could easily retain merely by refusing to 
be coerced? 

Well, I shall come to the point quickly. The hermit 
crab, acting solely by an instinct that he has undoubt- 
edly inherited from his ancestors, is a notorious bully. 
Therefore, his display of force is only a fraud, a sham 
whereby he terrifies or startles his opponent out of his 
wits and out of his retreat. It is a question of nerves. 
The one with the most temerity wins. 



Chapter VII 
SOME FRIENDS IN ARMOR (Continued) 

The peregrinations of our gladiator do not take 
him very far before he meets with a female. The 
latter, who is less than a third as large as the other, 
does not perceive him until he swoops down upon her 
from an ambushing frond of sea lettuce over which he 
has crawled. Instantly she withdraws completely into 
her shell and covertly watches him. When he reaches 
her he rolls over her shell, then stands above her wait- 
ing for her to emerge. It is not long before her an- 
tennae are thrust out, followed immediately by her fore 
body. Whereupon he seizes her by a rear leg and re- 
tains a secure hold. The art of coquetry seems not to 
be absent even among the lowly, for she makes a great 
pretense at resistance and vainly endeavors to free her- 
self. But he will not be denied. The rogue is a cool 
lover; ardency in his make-up, though not wanting, is 
without tenderness; he deliberately pulls her after him 
while he continues his perambulations. 

Now and then they halt. In these periods he idly 
and mechanically scrapes the sand for atoms of food 
that he does not desire, but which she eagerly devours 
when they drift her way. By this time she has ceased 
her resistant efforts and resigns herself to him without 



104 Dwellers of the Sea and Shore 

further protest. For the greater part of an hour they 
continue their sauntering; she in the meanwhile remain- 
ing in his tenacious grip. The monotonous watch 
makes me weary of waiting. 

At length, however, his behavior changes. Facing 
her, he gathers her to him, and with a sudden move- 
ment brings her fore body clear of her shell. She 
accepts his embrace; and it is in this brief moment that 
a future generation of hermit crabs is assured. 

These amatory embraces of the freebooter are re- 
sumed at intervals of a half to three quarters of an 
hour or more. But at no time does he release his hold 
on her leg. And he would, no doubt, continue to re- 
strain her for the greater part of the forenoon but for 
the occurrence of the inevitable. The nuptials are 
rudely disturbed by the intrusion of a stranger. 

The hermit crab who now comes upon the scene is 
formidable not merely in bulk but in appearance, also. 
Gauzy sprays of red seaweed float from the ends of 
each feeler, and from the joints of his fore legs stream- 
ers of green flutter at every step; all of which give 
him the aspect of a warrior bedecked in the panoply of 
battle. The presence of these vegetal growths indi- 
cates that he is old. Although old he may be, he as yet 
shows no trace of senility in his movements, a circum- 
stance apparently not lost upon the other male. 

Viewing the other's approach with no little pertur- 
bation, the apprehensive swain signalizes his concern 
with a menacing gesture of his free claw; then uncere- 
moniously rolling his smaller mate under him, crouches 
with his fore body over her and assumes a belligerent 
attitude. 



Some Friends in Armor 



105 




106 Dwellers of the Sea and Shore 

The plumed knight does not even hesitate, but 
quickly engages the other. It is soon over. The more 
youthful one, receiving a painful pinch on the eyestalk, 
is overwhelmed by the onslaught and retreats inglo- 
riously, leaving his mate to the mercy of the dauntless 
aggressor. He does not go far, however, before he 
recovers from the assault and decides to come back. 
Whether he returns to take issue with the big male, or 
to retrieve the female, it is not easy to say. Perhaps it 
is for both reasons. At all events, when he reaches the 
spot again, he halts in evident surprise at the sight that 
greets him. The handsome stranger, adding insult to 
injury, now holds the female and is paying assiduous 
court to her. To make matters worse she accepts the 
other's blandishments in complete indifference to her 
late lover's presence. Never was there more un- 
abashed effrontery. What at first bid fair to become a 
conquest of violence has now resolved itself into an 
affair of the heart. The friendliness that she entertains 
toward her new gallant is only too plain to be pleasant. 
But the jilted crab ventures no visible remonstrance 
beyond nervously twitching his antennae and flicking his 
claws, as if berating the fickle jade for her faithless 
conduct. 

The turning tide, now fast coming in, makes further 
observation difficult. As I am curious to follow the 
history of the new-matched pair to its conclusion, I 
gather him with the decorated joints and plumed an- 
tennae clinging fast to the female's leg, which my inter- 
ference does not cause him to release, and place them 
in a pail of sea water to be transferred to a tank in 
my laboratory. 



Some Friends in Armor 



107 



Although it may not be termed a hardy creature 
when compared with some other inhabitants of the sea, 
the hermit crab can be raised successfully and be made 
to round out the natural span of its life in the artificial 
environment of the indoor aquarium. It is here, there- 




MALE AND FEMALE HERMIT CRABS. THE FEMALE IS THE SMALLER CREATURE 
PERCHED OH THE LARGER SHELL OF THE OTHER. 



fore, that I propose to trace those phases of its history 
impossible of determination in its natural habitat. 

There is strong reason to believe that the female 
can give birth to fertile eggs a year after the attentions 
of the male, but the time between mating and the emis- 
sion of the eggs is generally much less. It is, however, 



108 Dwellers of the Sea and Shore 

subject to considerable variation, and may range from 
a few hours to several weeks. 

As was indicated, the mother attaches her eggs to 
the hairs of her abdominal appendages. Here they 
hang suspended like clusters of miniature grapes. 
The number of units in a cluster is not large, averaging 
perhaps not more than three hundred. Indeed, this 
number is surprisingly small when one considers the 
enormous broods of some other crustaceans. The 
blue crab, for instance, will produce in a single spawn- 
ing 1,750,000 eggs. However, as the female hermit 
crab gets older her fecundity increases, but the incre- 
ment is not enough materially to change the average 
given above. Her eggs are a deep cherry red in color, 
and in size no larger than the period ending this sen- 
tence. Each one is suspended in a membranous sac 
which in turn is attached by a short thread to a bristle 
on one of the forementioned appendages. Receiving 
no other care than an occasional brushing to keep them 
free from particles of dirt, they are carried for a fort- 
night before they are ready to hatch. 

But in the meanwhile some remarkable changes have 
been taking place. By tearing apart, under the dis- 
secting microscope, an egg which is but a day old, the 
differentiation of organization can be seen making 
its first appearance. That mysterious transformation, 
due to those unfathomed forces that cause the cells of 
all organic structures to assume their predetermined 
arrangement, has just taken place. Nearly a week 
later, examination of one of the spherical units will 
show that the yolk comprises nearly half of its bulk; 
while in the remainder of the egg content can be traced 



Some Friends in Armor 109 

the dim outlines of the nascent larva. Each succeeding 
day is marked by a gradual but very definite change in 
the embryo; until finally the wee animal acquires a seg- 
mented hind body, a large tail fan, and a pair of un- 
stalked eyes. A more dissimilar offspring from the 
crawling adult could hardly be imagined. Its muscular, 
ringed abdomen and its broad tail now fit it preemi- 
nently to lead a roving life at any depth. 

The moment for hatching comes. It has been sig- 
nalized some hours before by a restless activity on the 
part of the larva in its apparent efforts to burst the two 
walls that confine it. Suddenly these are split length- 
wise and the wriggling youngster emerges headfirst 
through the rent. It has no chance to linger as it is 
caught immediately by the respiratory currents of the 
mother and sent hustling away. A common impulse 
now seems to animate the brood, and within a few 
hours the remaining larvae abandon forever the pre- 
cincts of the maternal shell. The mother then de- 
taches the sw r addling clothes still adhering to her; and 
soon following the departure of her young she sends 
bag and baggage flying after. 

Thenceforth each little crab pursues its uncertain 
fortunes alone. After a lapse of five or more weeks — 
during w r hich it molts not less than four times, increas- 
ing in size and acquiring a more adultlike character 
with each shedding of its crust — it settles to the bottom 
and finds a tiny shell. 

Such is the manner in which the hermit crab is 
ushered into the world. A rapid survey of his future 
shows that before the winter gales will have forced 
him into deeper water, where he will pass a dormant 



no Dwellers of the Sea and Shore 

existence, he will have molted once more and attained 
a quarter of an inch in length. The following summer 
will find him considerably larger, and by the third 
year he will have arrived at the period of sexual 
maturity; whereupon he will begin to take notice of 
his fellows, both males and females. From this time 
onward his feastings, fastings, fightings, and love- 
makings will continue. About two years later, realiz- 
ing that the business of life is done, he will crawl under 
the shelter of a rock or frond of seaweed and die. 

It is a natural impulse for us sentimental humans, 
when contemplating these lowly creatures whose em- 
ployments have excited our interest, to exaggerate, 
somewhat, their mental capacities. Intimate knowl- 
edge of their ways, however, reveals the disappointing 
proof of a cerebration almost incredibly restricted in 
its range. But, regardless of the measure we may give 
to their intelligence, it is likewise a common experience 
at times to wonder what thoughts — if such an attribute 
can be said to distinguish invertebrate animals — are 
passing through some spineless brute's brain. We wish 
to be transformed by some magic power for a brief 
period, and to be reduced to the same mental plane in 
order to glean a glimpse of that strange psychology of 
another world, a world so mysterious that a moment's 
consideration leads us at once to recognize that here 
we have to deal with factors which have barely any- 
thing in common with human understanding — which is 
to say, the behavior of the invertebrate is governed by 
impulses that have little resemblance to intellectual fac- 
ulties as we understand our own. 

In truth, a thoughtful consideration of all lower- 



Some Friends in Armor ill 

animal intelligence brings the inevitable conclusion that 
we are powerless to penetrate even the outlying boun- 
daries of that incomprehensible domain. As we de- 
scend from the intelligence of man, from his exercise 
of pure reason, through instinct, through so-called re- 
flex action to the sentiency of one-celled organisms, we 
find that at each receding level the barriers to that 
awful frontier become more and more impassable. 

The mind of humans or what passes for such among 
the lower animals is not a thing that can be subjected 
to the crucible or the retort. It cannot be weighed or 
measured. The instrument is yet undreamed of, which 
can register in the slightest the difference in kind or in 
degree between the mentality of mankind and the 
abysmal consciousness of the protozoan. The analysis 
of this thing which is without substance, form, or color, 
but which is nevertheless a tremendously real entity, is 
confronted by perplexities unknown to other investiga- 
tions of the experimental worker. 

Without wishing to anticipate myself, I am con- 
strained to admit at once that the fragments I have 
gathered in regard to the status of the hermit crab's 
intelligence have added but little to the meager balance 
in its favor. Actuated entirely by instinct, prompted 
solely by the exigencies of the moment, it is in none of 
its pursuits guided by the faintest glimmer of reason. 
In the conduct of its courtship, in the search for food, 
in fact, in its entire deportment throughout the whole 
tenor of its life, it is motivated by a mind that is little 
superior, and in many instances inferior, in its mani- 
festations to the movements of an automaton. 

The primary attribute that distinguishes intelligence 



112 Dwellers of the Sea and Shore 

as such, is memory. I need go no further than to illus- 
trate by example the doubtful possession of this faculty 
by the hermit crab in order to substantiate the above 
indictment. The reader has seen that in the natural 
habitat of the crab, the waters of the seashore, a meet- 
ing of the males precipitates a brawl. It is the same on 
their introduction to the large tanks of my laboratory. 
In their new environment, however, these quarrels are 
not resumed indefinitely; eventually they resign them- 
selves to a peaceful toleration, and share their quarters 
with indifference, if not with genuine amity. Beyond 
the usual attempts to filch one another's food, it is 
extremely infrequent that further hostile demonstra- 
tions occur. But what is more to the point is the fact 
that two males, when confined in a small half-gallon jar, 
never, after the first few hours of their acquaintance, 
renew, or rather exhibit, the slightest animosity toward 
each other. This circumstance, when considering the 
natural pugnacious propensity of the crab, is remark- 
able. What, therefore, does it signify? Does it mean 
that they have a memory for faces, so to speak? 

Let us see. From a small circular jar in which two 
males have lived at peace for several months, I remove 
both and transfer them to one of the same capacity 
but of a rectangular shape containing a different ar- 
rangement of seaweeds. Immediately their former 
friendship is forgotten; a fight ensues; and one or the 
other generally loses his shell in the encounter. After 
they have settled their differences, I return them to 
the first jar; but no sooner do they come into contact 
than they again fall to, with the same result. 

What could be plainer? The hermit crab either 



Some Friends in Armor 113 

has no memory or this memory in him is so feeble as 
to carry him only to the point of recognizing a strange 
environment. Beyond this he fails to apprehend any- 
thing else — not even the identity of his old companion. 

If this inference be correct, we may reasonably ex- 
pect to find that their transference to a corresponding 
container will result in no display of belligerence. And 
this is what we do find. The similarity of their sur- 
roundings misleads them into accepting the new T er as 
their customary home; and as there is nothing un- 
familiar in the newer place, they do not mistake each 
other for strangers. But this is not all. If I now drop 
a strange crab from one of the larger tanks into their 
presence, neither of the tw T o original occupants seems 
to be aware of the addition until compelled to defend 
himself from the inevitable onslaught of the newcomer. 

One more word regarding this matter. Near a 
north window in my study stands a rectangular aqua- 
rium holding about twenty gallons of salt water. In 
one corner of this miniature replica of the seashore 
bottom is a large brown anemone (Metridium margi- 
natum) attached to a rock. Among the other animals 
with which the aquarium is stocked are several hermit 
crabs of both sexes. Conspicuous among these is a 
singularly huge male who by reason of his decrepit 
appearance and obviously old age drew from my chil- 
dren the alliterative, but fanciful, name of Hank the 
Hermit. Throughout the past winter Hank's great 
diversion, apart from exploring the nooks and inter- 
stices of the gravelly floor, and giving battle to imagi- 
nary enemies concealed in those retreats, w r as to make 
daily tours with monotonous regularity around the 



114 Dwellers of the Sea and Shore 

glazed confines. In the direct path of these excursions 
stood the anemone. Now it seems not to be one of 
the traits of the crab when meeting with an obstacle 
to choose the more sensible and easier method of going 
around it; instead, his course is an attempt to go di- 
rectly over it. This was Hank's intention whenever he 
came upon the anemone; but the contact of his feelers 
with the arms of the coelenterate caused him to recoil 
with surprise. It may be interposed here that, al- 
though the touch of the anemone's tentacles is deadly 
to very small organisms, their potency is quite lost on 
the tough armor that encases the fore body of the 
hermit crab. Still, their power is considerable, as I 
have had occasion to learn by testing with the tip of 
my tongue; and I have no doubt, therefore, that the 
sting is as acutely felt with those delicate tactile organs 
of sense, the antennae of the crab. 

As the unpleasant contact with the anemone was 
assuredly one to be avoided, it might well be assumed 
that after three or four repetitions of his blunder, 
Hank would give that animal a wide berth. But three 
or four hundred repetitions failed to inculcate in him 
the slightest recollection of the dangerous spot. Time 
and time again, on his perpetual rounds he would 
blindly walk into the tentacles, never learning by ex- 
perience or memory to avoid their painful touch. 

Now, it has doubtless struck the reader long before 
this that it is a somewhat unfortunate, as well as a 
curious, circumstance for the hermit crab to be marked 
among all crustaceans by the double affliction of pos- 
session of a weak body and being obliged to bear a 
burdensome load throughout the greater part of his 



Some Friends in Armor 115 

life. That he was not a weakling, however, in the 
remote history of his race, is not only revealed by the 
internal evidence of his structure, but, if the statement 
of men learned in the evolution of life, that in the 
embryological and larval phases of animals are roughly 
recapitulated their ancient forms, be correct — and 
there is reason in abundance so to believe — there is 
more than a hint in the development of the living 
hermit crab that he did not always require a borrowed 
shell for his protection. 

As fossil remains of crustaceans have been so 
meager, there is, of course, no way of picturing with 
absolute certainty the true appearance of the hermit 
crab's ancestor. Nevertheless, without going into 
tedious technical details, I will say that anatomical 
considerations alone strongly support the inference that 
the forerunners of the crab were endowed with a seg- 
mented hind body, and that they in general were 
distinguished by a much higher physical develop- 
ment. 

It is, moreover, well known that the crustaceans 
appeared on this earth long before the mollusks. 
Therefore, it may be assumed that the utilization of 
dead shells by the crab is an attainment of a compara- 
tively recent date. Nor is it unlikely that his propen- 
sity for secreting himself in crevices or crannies to 
await his prey, eventually led him to hide in empty 
shells. It needed only a further lapse of time for him 
to acquire the habit of carrying these advantageous 
coverings with him. But this restricted his movements. 
And the new mode of living lost him the pristine vigor 
of his body. What is more, the descent from the apti- 



1 1 6 Dwellers of the Sea and Shore 

tude for a predatory life to the less alert existence of 
a scavenger has lost him his sagacity. 

I am now obliged to make a painful admission. In 
summing up all the evidence, it is only too apparent that 
the hermit crab is an animal which long ago reached 
its highest development, and is now on the decline. In 
a word, the hermit crab is a degenerate. 



Chapter VIII 
MARINE GROVES AND GARDENS 

As our knowledge regarding the nature of living 
things increases, it becomes more and more evident that 
the difference which is presumed to exist between the 
plant and the animal kingdom is at best an artificial one. 
That is to say, plants and animals are essentially the 
same. It is true that we recognize plants by certain 
characteristics, such as form, color, or development — 
characteristics not commonly found among animals — 
but, after all, a little reflection will show that these 
distinctions are more or less superficial. There is, in 
fact, no single attribute of fundamental importance to 
the life processes that can be said to belong wholly 
within the province of either kingdom. 

The chief biological difference that distinguishes 
plants as such is in their capacity to utilize the sunlight 
in transforming certain elements into parts of their cell 
structure, and their ability to form organic compounds 
from elements existing free in nature or derived by 
breaking down inorganic compounds. This somewhat 
technical statement is only another way of saying that, 
whereas the truly typical animal can eat only substances 
already manufactured, such as plants or Dther animals, 
the plants, on the other hand, manufacture their own 

117 



1 1 8 Dwellers of the Sea and Shore 

food. But even this statement, although essentially 
accurate, is subject to qualification. Numerous excep- 
tions abound. As a matter of fact there are some 
animals which are nourished like plants, and there exist 
certain plants which subsist only on food material 
already formed. 

Now all this is not to say that what are commonly 
recognized as plants are animals in masquerade, or 
the reverse; it is, however, a way of stating that the 
gulf between them is far more apparent than it is real. 
Between the higher individuals of both kingdoms the 
relationship, of course, is not so generally obvious. 
But when we turn to the lowest of all living forms, 
the one-celled organisms, an undisputable kinship mani- 
fests itself. Indeed, there occur among these some 
which have identities that are neither distinctly plant- 
like nor are they truly animallike ; rather they are both ; 
that is to say, they are half vegetable and half animal. 
The little green Euglena of fresh-water ponds and 
streams is a classical example of organisms which, so 
to speak, are on the borderland. This pretty, but 
paradoxical, creature — if I may so call an organism 
which is also an undoubted plant — has given rise to 
considerable friendly controversy among naturalists as 
to its proper place in nature. Botanists as well as 
zoologists claim it as their own. 

But our lowest plants merit an attentive considera- 
tion quite aside from any of the foregoing reasons, for 
they are presumed to be the present-day representatives 
of the first living things to appear on this planet. The 
history of the earth is a thrilling record of vast and 
impressive changes, not only in the appearance and the 



Marine Groves and Gardens 119 

very structure of its surface, but in the succession of 
living forms which have inhabited it. Yet the simplest 
plants have outlived them all. Many there are that 
have persisted unaltered throughout the countless ages 
that saw the appearance and disappearance of mighty 
hosts of higher forms. Ancient as is animal life, the 
lowly plants probably antedate them by a period so 
great that in comparison the existence of the former 
would seem to be but of a day. 

It is, therefore, with peculiar interest that we turn 
to the vegetation in the sea, for, as was pointed out 
in a previous chapter, this region was the probable 
source of all life. This vegetation, with very few 
exceptions, is comprised entirely of the lowest forms 
of plant life. Now this will appear strange to the 
reader whose limited acquaintance with the seaweeds 
has led him to look upon their varied and ofttimes 
beautifully branched fronds as structural counterparts 
of land plants. As a matter of fact, however, they 
have nothing in common with the higher terrestrial 
types. Seaweeds all belong to that division of plants 
termed thallophytes. All thallophytes living in water 
and obtaining their nourishment directly therefrom are 
further distinguished by the name alg&. It is for the 
reason that they are composed of one class of cells that 
algae are the lowest and simplest of plants. In this 
respect, it must be borne in mind, the familiar flowering 
plants are totally different. The groups of cells which 
constitute the stem and the leaf and various other parts 
of the plant are vastly unlike in their character and 
function. In the higher forms of marine algae, the 
vegetative body is called the frond. The disk or ex- 



120 Dwellers of the Sea and Shore 

pansion of the base of the plant is the holdfast. This 
latter, although corresponding to the root of a flower- 
ing plant, does not, in the real sense of the word, per- 
form the office of that member any more than the frond 
functions as a flower or a leaf. Roots absorb the 
nourishment for the entire plant. The nourishment 
derived by algae from the substances held in solution 
by the surrounding water is due to the work of every 
individual cell composing the plant. In other words, 
beyond the fact that it is in physical attachment to its 
neighbors, each cell lives as a unit and without refer- 
ence to the rest of the colony. 

Notwithstanding its fundamental simplicity, the 
diversity in the structure of marine algae is very great. 
In the lower orders a single cell constitutes the plant 
body. These forms are mostly microscopic. Next in 
point of development are those like Cladophora } which 
consist of single threadlike rows of cells. Then comes 
Ulva, in which is found the earliest type of expanded 
frond. Here the cells are arranged in a horizontal 
surface forming leaflike or ribbonlike expansions. In 
Enteromorpha there is a double layer of these cells 
which separates, giving the seaweed a hollow, or 
tubular, form. From here on the complexity increases 
until in Sargassurn, or gulfweed, we see the most dif- 
ferentiated of all marine plants. In this form there 
are slender branching fronds bearing various kinds of 
lateral members, some of which are like ordinary foli- 
age leaves supported on stems; others are round air 
floats resembling clusters of berries; and still other 
branches bear remarkable sex organs. 

Not merely do the marine plants compare favorably 



Marine Groves and Gardens 



121 



with those of the land in diversity of form, but they 
surpass them in linear size. The huge floating fronds 
of Laminaria, whose stalk develops great rootlike hold- 
fasts, are frequently ten or more feet long. But the 




sargassum; the gulfweed. 



lessonia; a laminarian seaweed. 



largest plant in the sea, and, for that matter, the great- 
est in height in the whole world, is an Antarctic lami- 
naria. This extraordinary seaweed rises from the 
sloping bottom of the continental shelf with a frond 
nearly a thousand feet in length. Other large lami- 
narian forms grow on the sea bottom like trees, hav- 



A 



egregia; a laminarian seaweed. 
122 



Marine Groves and Gardens 



123 



ing thick trunks, numerous branches, and leaflike 
appendages. 

Seaweeds also exhibit considerable diversity in color, 
and this feature has caused their being divided into 
four great groups. These groups, or subclasses, a r e 
the blue-green algae (Cyanophycea) , grass-green algae 
(Chlorophycece) , the brown algae (Phaophycea), and 
the red algae (Rhodophycea) . These are again sub- 
divided into various genera and species, and the num- 




MACROCYSTIS: A LAMINARIAN SEAWEED. 



ber of the latter so far known and classified is said to 
be several thousands. 

As is the case with shore animals, the most favorable 
time for collecting or observing the range and distribu- 
tion of seaweeds is during low tide. A walk along 
almost any shore at this time will show that these 
humble forms are as particular in their choice of 
locality and character of their neighborhood as are the 
higher plants of the land. Just at the high spring 
water mark will be seen some sturdy types of a short, 
stubby growth, which seem equally at home out of the 



124 



Dwellers of the Sea and Shore 



water as well as in it. Living here for many gen- 
erations, they have attained, as the result of long- 
continued exposures by the intermittent tides, an un- 




enteromorpha; a green seaweed. 



usual hardihood for sea plants. Others which have 
more recently taken to living here exhibit traces of the 
fight to maintain their new positions in their emaciated 
and starved appearance. They have not yet acquired 
the ability to withstand prolonged absence from the 



Marine Groves and Gardens 125 

water. Lower down, these same plants can be seen 
growing; but in this place, well within the washing of 
the waves, they are robust and vigorous. 

Not far below the line reached by the ordinary tides, 
especially in neighborhoods of streams, or estuaries 
where brackish water prevails, a bright fringe of green 
skirts the shore. This consists largely of the con- 
fervoid algae, or silkweeds, whose fine, filamentous 
fronds sometimes grow in tufts so dense that they are 
matted at the base. But in close company with these 
also grow many others. Here we find Enteromorpha 
\ntest\nal\s y whose tubular, inflated fronds have given it 
its characteristic Latin name, and its sister plants, E. 
clathrata and E. eompressa. Here, too, occasionally 
attached to larger algal forms or lying loose in drifted 
clumps, are the pretty locks of mermaid's hair, a blue- 
green seaweed with the curious scientific name of 
Lyngbya majuscula; and occurring in spreading patches 
are the minute threads of Oscillaria and Spirulina, 
strange, restless plants which under the microscope 
exhibit a ceaseless vibrating movement. Then we 
come to the water, where Viva abounds. 

Who has not heard of "sea lettuce"? Ulva, which 
almost universally goes by that name, is the commonest 
and best known of all the seaweeds. That this is so 
is not because of its greater abundance, for there are 
many others far greater in numbers if not in range, 
or because it is the largest of all green seaweeds, 
therefore the most conspicuous, but it is by virtue of 
its association with those bays and inlets of a type 
whereon mankind has always been wont to congregate. 
It is identified with nearly every seaport and harbor 



126 



Dwellers of the Sea and Shore 



in the world. The reason for this is plain. Its form- 
less fronds, often measuring several feet in length and 
breadth, are as thin as a newspaper. Thus they pre- 
sent a considerable area to the action of the waves; 
and although they can withstand the tempered move- 
ments of sheltered waters, they could never endure the 




ulva; the sea lettuce. 



surging swells of the open coast. To say that Ulva 
is a beautiful seaweed would be to venture a praise 
more enthusiastic than critically just. Yet Ulva has 
its merits. Its broad, green, crispy fronds glisten like 
silk in the sunshine and forming as they do acres of 
veritable marine gardens they may well be included 
among the rarest of nature's lovely spectacles. And 
how the fishes love to sport among the lifting folds ! 



Marine Groves and Gardens 127 

The sea lettuce is the common food of many creatures 
of the sea. Indeed the human species itself has not 
disdained to make it serve its needs. Under the name 
of "oyster green" this seaweed was once prepared for 
the table as a wholesome delicacy. But its value to the 
animals of the sea is twofold; besides serving as a 
source for food it gives off considerable oxygen in the 
water so that they may breathe. While all seaweeds 
give off more or less oxygen this property of Ulva is 
noteworthy and for that reason it makes a most desir- 
able plant for aerating the indoor aquarium. It adapts 
itself readily to confinement and will thrive in situations 
that are fatal to other marine plants. 

Next to Ulva, perhaps the most familiar seaweed is 
Fucus. Fucus, or the roekweed, is far different from 
Ulva, however, in color, form, and habitat. It is one 
of the brown seaweeds, although its color is more often 
an olive green, and grows in its greatest profusion 
between the tide marks on exposed rocky shores. The 
tough and leathery texture of this plant denotes its 
character. Holding fast with its suckerlike disk to the 
rocks of rugged shores, it breasts with impunity the 
shattering force of the driving surf. But its hardiness is 
exemplified not merely in the ability to live in a pound- 
ing sea; it thrives throughout the winter, and, under 
the scorching rays of the summer sun, during the fall 
of the daily tides, it survives temperatures that would 
shrivel the sea lettuce into a formless cinder. 

In further contrast to the simplicity of green sea- 
weed is its higher organization, or differentiation of 
parts. Some members of this genus have a distinct 
midrib. All the plants are forked and flat; that is, 



128 



Dzvellers of the Sea and Shore 



they are expanded in one plane like an oak leaf. A 
distinctive feature, and one which marks quite an ad- 
vance in the development of seaweeds, is its possession 
of air bladders and conceptacles, or spore chambers. 
The air vessels enable the somewhat thick and clumsy 
fronds to uplift themselves in the water and thereby 




FUCUS, AN OLIVE-GREEN SEAWEED, GROWING ON A ROCK. 

maintain a position most favorable for the assimilation 
of light and nourishment. When thus seen swaying in 
the depths, their beautiful bouquetlike forms bend to 
and fro with indescribable grace. 

It is in the peculiarity of its spore chambers, how- 
ever, that Fucus particularly solicits attention. For 
here we find the beginning of that complex process of 



Marine Groves and Gardens 129 

reproduction which is later to be found in such per- 
fection among higher plants. In fact, this alga carries 
on its spore production in a way that is already as 
involved as the formation of seeds in flowering plants. 
The conceptacles are usually grouped at the extremities 
of the frond, and are easily identified, as their surface 
has a pimpled, or rough, appearance. Now Fucus is 
heterogamous; this means that the individual plant 
bears both the male and the female sex organs. The 
eggs and sperms are discharged in the water inde- 
pendently. The eggs float freely and without motion; 
but the sperms each possess two cilia arranged in a 
fore-and-aft manner, and these latter, being in a con- 
stant state of vibration, enable the organism to swim 
about. So small are these sperms that many hundreds 
can be contained in a drop of sea water. The eggs 
are considerably larger, though their details cannot 
be resolved without the aid of a good microscope. As 
the egg floats passively in the water, in some mysterious 
way — supposedly by chemical action — it attracts great 
numbers of male cells to it, and these arriving in such 
force, frequently set it to rotating by impinging against 
it. Yet of all the host that seek it, only one is 
favored. A fusion finally takes place, and the now 
fertile egg drifts around for a while, eventually finding 
a favorable lodging place on some rocky shore where 
it later develops into a new plant. 

As Fucus must find a firm support to which to attach 
itself, it is obvious that its presence on the Atlantic 
coast would be relatively rare south of Long Island, 
for below this region great stretches of sandy beaches 
prevail. There does exist, however, in the deeper 



130 Dwellers of the Sea and Shore 

waters off those shores, a brown seaweed closely 
related to Fucus, whose differentiated fronds, closely 
resembling the structure of higher plants, are often 
torn from their anchorage and found washed up on the 
beach. This is Sargassum, of which mention has been 
made before. Two plants of this genus, 5. vulgare and 
S. montagnei, both of which measure less than three 
feet in length, are found as far north as Cape Cod; 
but a larger species, S. bacciferum, known as the "gulf- 
weed," grows off the shores of Florida. This latter 
seaweed has acquired considerable prominence from 
the fact that it composes the major portion of that 
extraordinary floating mass of vegetation circling 
about in the great sea eddies produced by the Atlantic 
currents and forming the so-called Sargasso Sea. 
After being carried far from their place of origin 
many of these plants continue to grow in this mid- 
ocean tangle as luxuriantly as on their native shores. 

Many of the brown seaweeds are of economic im- 
portance. Particularly noteworthy in this respect are 
the giant laminarians of the Pacific coast commonly 
called sea wrack or kelp. Kelp is harvested by boats 
equipped with special machinery for the purpose. 
These ocean reapers bring in great barge loads of this 
free-for-the-collecting freight from where it floats in 
huge fields, and turn it over to industrial organiza- 
tions which convert it into iodine, potassium chloride, 
and other by-products. Its high potassium content also 
allows it to be dried and used in that way as a soil 
fertilizer. 

The large proportions of the kelps make them easily 
the fastest growing plants in the vegetable kingdom, 



Marine Groves and Gardens 131 

as they attain their full growth within a year. One of 
these is reported as having a stem of the thickness of 
a clothesline and reaching the length of nine hundred 
feet; along the greater part of this ropelike stem are 
attached numerous expansive u leaves." Another, the 
bladder wrack, has a stem the length of which measures 
a hundred and fifty feet. But, although its stem is 
relatively short, it is distinctive in having at the end 
a great globular float bearing leaflike appendages over 
twelve feet long. 

Except for those low, invisible, fungous forms, the 
bacteria, marine vegetation is entirely restricted to the 
surface of the sea and its shallow waters. This limi- 
tation is obviously far short of that of the animals, 
who, as will be revealed in a later chapter, range to 
the greatest known depths. Now the reason for this 
restriction would not be hard to guess, even though 
our knowledge of conditions generally regulating the 
growth of plants on the sea floor were ever so imper- 
fect. The chief factor, of course, is light; for the sea- 
weeds are no more able than are their land relations 
to live beyond the reach of the sun's rays. The amount 
of light that penetrates the sea rapidly diminishes with 
increasing depth; therefore, few living plants are 
found much lower than a hundred and fifty feet. 

Yet even at this level they do not sensibly decrease 
in numbers. They are, however, greatly reduced in 
size. Nor is this the only change. They are exten- 
sively altered in character. In fact, it is here in these 
remote regions, where filter feebly the last remaining 
rays of light, that flourish the most varied, the most 
colorful, the most exquisitely delicate and, in many 



132 Dwellers of the Sea and Shore 

ways, the most beautiful forms of plant life. These 
are the red algae. 

Although red is their prevailing color, they exist in 
hues ranging from a delicate pink to deep purple, and 
these sundry shades, ordinarily the most pleasing of 
the spectrum, seem to acquire an unwonted beauty in 
the filmy or filamentous or ribbonlike structures of 
some of these seaweeds. Often a profuse branching 
occurs, and the plants resemble mosses or ferns. But 
such mosses, such ferns ! Nature has no parallel, in 
any higher plant, for tint or texture. This red color, 
by the way, is only a mask. In spite of its predom- 
inance, there exists in these plants a large amount of 
chlorophyll, the green coloring matter that character- 
izes Ulva and the higher forms of vegetation, and 
that by some subtle alchemy converts the sunlight into 
plant food. 

All red seaweeds are anchored forms. Moreover, 
as I have pointed out, they are particularly identified 
with the deepest waters in which algae will grow. But 
it by no means follows that they are restricted to the 
deeper parts; they are, in truth, to be found living as 
high as the tide marks. The numbers and species, how- 
ever, grow fewer as the higher levels are reached. 
This latter observation also may well be applied to 
their range as it extends northward; for they are es- 
sentially plants of temperate and tropical seas. In this 
connection mention of the corallines will not be out 
of place. This remarkable group of seaweeds, mostly 
displayed in the warm waters of tropical shores, se- 
cretes so great an abundance of lime in the cell walls 
that the plants become deeply incrusted and resemble 



Marine Groves and Gardens 



133 



branching corals. It is on this account that they are 
called corallines. A representative type, though one 
which by no means attains the perfection and beauty of 
the tropical forms, is the common coralline (C. offici- 
nalis), found in tide pools and on rocks at low-water 
mark on New England shores and in Long Island 




corallina; a red seawff.d which resembles coral. 



Sound. Its rigid, jointed, and many-branched frond is 
often mistaken, by those unfamiliar with its real 
nature, for coral, to w T hich it has some resemblance. 

In the territory just mentioned, the amateur col- 
lector will also often find washed ashore many of the 
deeper forms, such as the brilliant Griffithsia, so named 
for an English algologist, Ptilota the feather weed, 
Hypnea the moss weed, and Phxllophora the leaf weed. 



134 Dwellers of the Sea and Shore 

But he need not depend on the chance of the waves 
to start his acquaintance with this interesting group; 
an abundance of living forms will be found growing 
well within his reach. Of the genus Polysiphonia alone, 
there are over two hundred named species. If it so 
happens that he is fortunate enough to possess a micro- 
scope, some startling revelations await him in the exam- 
ination of the structures of these threadlike plants. 
Under that instrument a filament becomes a bundle 
of filaments, or tubes, surrounding a central tube. 
These tubular parts are called siphons, and from them 
Polysiphonia (meaning "many tubes") gets its name. 
In some species the siphons are bare, and the filaments 
are banded with alternate rings of color. In others, a 
surrounding layer of corticating or bark cells cover the 
siphons, giving the filament an unmarked, uniform, but, 
nevertheless, attractive appearance. 

Then there is Ceramium, the pitcher weed. This 
also shows to its best advantage under the microscope. 
Like Polysiphonia, it is banded, but its forked filaments 
are not made up of siphons. Another is Callitharnnion, 
a soft, silky seaweed of cobweb fineness. This plant, 
too, is represented by many species; they grow in crim- 
son tufts, and along each gauzy filament are dense dots 
of deep red. 

However, the want of a microscope should not deter 
the ambitious beginner; a good, strong pocket lens will 
often serve him well. I shall add, moreover, that even 
the latter could be dispensed with, and there would still 
remain a numerous host whose obvious details would 
not fail to excite his wonder and delight. 

Notwithstanding that the red seaweeds are found in 



Marine Groves and Gardens 135 

adverse situations, flourishing under the most unfavor- 
able conditions known to chlorophyll-containing plants, 
they have, nevertheless, reached the highest develop- 
ment of all marine algae. This is marked by their mode 
of reproduction. Now this is an extremely complex 
affair, and differs quite extensively in detail among the 
different members of the group. In fact, so involved, 
or modified, is it in some instances that it is as yet 
poorly understood, even by professed botanists. Still, 
I think that I can give some representation of the 
process as drawn from a very simple case, that will 
enable the reader to form at least a fair, if not com- 
plete, conception of its general nature. 

Red algae are peculiar and unlike other algae from 
the fact that they produce no swimming spores. Their 
reproduction is carried out in two ways. These are 
termed asexual reproduction and sexual reproduction. 
In asexual reproduction, the spores are formed in an 
envelope which, with its contained products, is called 
a sporangium. Since the sporangium usually, but not 
invariably, carries four of these spores, they are termed 
tetraspores. These upon being discharged in the 
water settle to the bottom and immediately start to 
germinate and produce new plants. It will be noted 
here that this method is quite different from that pre- 
vailing in the spores of Fucus. There is no fusion of 
cells prior to the development of the plants. This is 
the usual way in which red algae multiply. 

But there sometimes occur in the life of a plant 
extraordinary circumstances, somewhat like the winter 
season or other unfavorable periods experienced by 
land plants; and these unfavorable conditions must be 



136 Dwellers of the Sea and Shore 

bridged over in some way if the seaweed is to per- 
petuate itself. It accomplishes this through its most 
remarkable sexual reproduction. On a certain part of 
the frond it develops an organ called the antheridium. 
This gives rise to sperms which, like the tetraspores, 
are without cilia and are, therefore, unable to swim. 
However, instead of sinking to the bottom, they float 
about until they come into contact with another organ 
on the plant known as the oogonium. The oogonium 
is a bottle-shaped female organ with a long narrow 
neck. In the bulbous base is contained an egg. When 
the floating sperm reaches the oogonium it clings some- 
where along this neck, and, perforating the wall at the 
point of adhesion, it passes its contents to the egg, thus 
fertilizing it. 

Strangely, the immediate result of this fusion of the 
sex cells is not, as one would anticipate, the develop- 
ment of a new plant. Instead, the now fertile egg 
breaks up into numerous spores, and there appears in 
the place of the oogonium a fruitlike structure called 
the cystocarp. So what we have here is really a kind 
of sporangium or spore case containing asexual spores. 
But, unlike the tetraspores which cannot defer their 
development, these carpospores can await a favorable 
time or situation before proceeding to maturity; that 
is to say, before growing into a new generation of sea- 
weeds. We find, then, in summing up the life history 
of the red alga, that beside having two modes of re- 
production, asexual and sexual, they produce two sorts 
of asexual spores : The tetraspores, arising from a 
simple sporangium; and the carpospores, products of a 
fertilized egg developed within the cystocarp. 



Marine Groves and Gardens 137 

An acute observer once pointed out that there seems 
to prevail a natural rule to the effect that as an organ 
becomes more highly specialized or as plant and animal 
life becomes more advanced in development, the ability 
to regenerate injured tissues or lost parts becomes in- 
creasingly diminished. For instance, in higher animals 
the stomach, a primitive organ, can undergo consider- 
able mutilation and recover its pristine vigor, but the 
slightest damage to the more specialized kidneys is 
practically irreparable. Then, again, the facility with 
which lower animals, from the sponges to the crus- 
taceans, can grow lost parts, when compared with that 
of the vertebrates, is another case in point. Well, at 
any rate, whatever may be the value of this rule in its 
application to higher forms, it is certainly true so far 
as it is reflected by the seaweeds. With some doubtful 
exceptions, red algae cannot give rise to new individuals 
if the fronds are detached from the base. In other and 
lower forms, however, growth constantly proceeds re- 
gardless of an injury of this sort. This method of cell 
reproduction, know T n as vegetative multiplication, is 
carried to an extreme by many green seaweeds. A 
good example is Ulva. When it is in the growing stage 
it can be torn into any number of parts, and each one 
will continue to enlarge into a conspicuous frond. 

The seashore is the great evolutionary threshold of 
both plants and animals. I have already mentioned 
the fact that some of the marine algae are learning to 
live out of the water; but there are, on the other hand, 
not a few land plants which have taken to the sea. And, 
curiously, these for the most part are represented by 
the higher, or flowering, forms. This reversion to 



138 



Dwellers of the Sea and Shore 



their ancient habits is not in any sense to be taken as 
a form of degeneracy; they have, on the contrary, ac- 
quired an uncommon degree of specialization in order 
to adapt themselves to an aquatic existence. 

Like the seaweeds, these plants are intrinsically in- 
teresting, but they are especially noteworthy for their 
remarkable association with certain forms of animal 



1 '^|p?-""«k*l iVv 


m 




v%)^ 




w 


I, 




Y,^^ 
^ 


I, ... X 




• 



PRICKLY WORT; A FLOWERING PLANT OF THE SEASHORE. 



life. Seldom do we find a bed of eelgrass (Zostera) 
without a host of hydroids, snails, and other creatures 
living among its watery glades; even one or two red 
algae seem to prefer the slender leaves for their attach- 
ment rather than the rocks. The thatch (Spartina) 
and other plants of salt marshes and meadows are 
marked by some crustaceans as their very own. A 
species of fiddler crab (Uca pugilator) makes its home 
in such numbers in the muddy soil holding the thatch, 



Marine Groves and Gardens 



139 



that it is rarely looked for elsewhere by experienced 
collectors. 

Here I must conclude. It is not without a certain 
regret, however, that I do so. For, to me, there are 
few subjects more absorbing than that which forms this 
chapter. For the reader's proper understanding of 
that vast range of life which forms the groves and 




salt wort; a flowering plant of the seashore. 



gardens of the sea, I have necessarily been obliged to 
trace the briefest outline. But it would be a mistake 
for him to assume from this bare sketch that marine 
vegetation has no interest apart from what was occa- 
sionally pointed out. The plain truth is, there are 
periods in the life histories of various individual plants 
that are as dramatic and as charged with incident as 
those which arouse our emotions in the case of higher 



140 Dwellers of the Sea and Shore 

animals. To grasp those situations, of course, requires 
a sympathetic attitude, an interpretative spirit fostered 
by affection. This, however, will not be slow in assert- 
ing itself. One cannot long associate oneself with 
them before learning that one has not to do merely 
with an inanimate, growing form, but with a very vital 
thing. And this, by the way, is just as true of the higher 
plants as of the seaweeds. It is a singular thing that 
of all our companions on this planet, the members of 
the plant kingdom are the most serviceable and yet the 
most neglected. Almost every variety of animal has 
been revealed to us through the fervent praises of dis- 
tinguished pens. But where is there a Homer of the 
plants? Certainly, the answer is plain; and perhaps it 
contains the real reason why plants to the many always 
have been, and still are — just plants. 



Chapter IX 
FEATHERS AND FEELERS 

This account of shore life would be incomplete if 
no consideration were given to that distinct and most 
interesting association of animals which occurs in con- 
nection with the jetsam deposited by the tidewaters. 
Therefore, I purpose to take the reader to one of those 
spots in my neighborhood in which my frequent pres- 
ence has made me almost as familiar a part of the 
locality as the dune plants and beach grass that thrive 
in the sandy soil. The region whereof I speak is a 
narrow spit, some three fourths of a mile long by only 
a fraction of that in breadth, which almost completely 
bars the entrance to the marshy cove. This peninsular 
area is constantly changing in outline and topography, 
but in spite of the rapidly shifting ground, a prolific 
and numerous vegetation maintains its determined 
stand. Certain dune plants are trying hard to domi- 
nate; still, the strand is in no sense a typical dune. It 
is low-lying, and, with the exception of a sort of back- 
bone, or central ridge, the tides nearly submerge it. 

In addition to the great variety of shore life which 
crowds its tide pools and populates the sands, the iso- 
lated nature of the place, due partly to the wilderness 
of reeds flourishing in the slimy soil that connects it 

141 



142 Dwellers of the Sea and Shore 

with the mainland, and partly to the creek that sepa- 
rates it from the opposite shore, makes it particularly 
favored by the marsh hen and other birds — and by me. 
Here, more so than is possible at any other point along 
the harbor shore, I am able to install myself in some 
sequestered spot and follow also the actions of my 
humble friends of the sea, uninterrupted by the idly 
curious. Unfortunately, however, these advantages 
are growing less and less each year. The beach that 
lines the outer side of this barrier is the finest in the 
harbor. The bathers hereabout have discovered this, 
and every summer sees an increase in their numbers. 
On my own part, I have no selfish wish to see it other- 
wise ; for who am I to put a personal convenience above 
the happiness of the many? Yet it is not without 
emotion that I regard the effect these seasonal incur- 
sions will have on the welfare, of my pretty animals. 
Where are they going after being driven from their 
homes? No other place in this region offers such an 
ideal sanctuary. It is not large, but within its limits 
are contained a number of forms which, unable to 
thrive elsewhere, have sought it as the last remaining 
place of refuge. One of these, Limulus, the horseshoe 
crab, is, at best, fast becoming extinct; and it would be 
a pity to have this picturesque and inoffensive creature 
disappear from these shores entirely. 

During July and August the heat of the sun beats 
down upon this strip of sand with tropical intensity. 
It is the season most loved by the animals of the sea 
and shore. At this time they are at the height of their 
activities. A walk along the water's edge reveals a 
teeming population. Many of them, alarmed at human 



Feathers and Feelers 143 

approach, strike out in all directions with panic-stricken 
haste. The scampering of the fiddler crabs making 
their way up the slope to their burrows and the pro- 
gressive leaps of the minnow shoals are distinctly 
audible as a continuous, murmurous hum. Larger 
forms are also here displayed which do not take kindly 
to our presence. Almost under our feet the ebbing tide 
has left a molting lady crab. Partly buried in a puddle 
of silt, she fidgets uneasily, viewing us apprehensively 
with her twitching stalk eyes. Having been weakened 
by the profound physical change that she is undergoing, 
she was unable to swim out with the retreating water. 
But she need have no fear where we are concerned; 
far greater danger lies in the chance observation by 
some member of a flock of herring gulls now rising with 
a chorus of angry cries within a stone's throw of our 
advance. Nearing the spot where raged the recent 
tumult, we soon have no difficulty in learning why they 
resent our intrusion. High up on the beach is the 
stranded carcass of a fishing frog. The casting-up of 
these curious deep-water fish is not an uncommon occur- 
rence on this shore; although in what manner they 
meet their death is not readily apparent. I once found 
a specimen nearly four feet long which had a mouth 
more than a foot and a half wide; it was intact, 
bearing no external evidence of any mortal injuries. 
Nor, on cutting it open to examine the contents of its 
stomach, was there anything to indicate an unseemly 
death. Sometimes fishes are known to die from the 
effects of trying to eat over-large spine-bearing crea- 
tures which they are unable either completely to swal- 
low or to regurgitate. But the stomachs of those ani- 



144 



Dwellers of the Sea and Shore 



mals I have opened were generally filled to capacity only 
with herring or other small fishes in various stages of 
digestion — a circumstance, furthermore, which pre- 
cludes the probability of .death by sickness or starvation. 
For the reason that it is commonly supposed to allure 




FOOTPRINTS OF A HERRING GULL. 



its prey within reach of its great jaws by means of a 
dangling, baitlike organ at the end of a long modified 
spine on its snout, it is also variously called the sea 
angler or angler fish. 

In the confusion of tracks around the carcass on the 
sand are to be seen those of other birds beside the 
herring gulls. One conspicuous footprint, with deep- 



Feathers and Feelers 145 

taloned indentations at the ends of the toe marks, 
shows that some wandering buzzard has stopped to 
eat. Another is that of the great saddleback gull, 
a bold, well-marked imprint, a perfect intaglio of the 
sole of the web-footed maker. The crow, too, has left 
its characteristic mark. But it needs no telltale foot- 
prints here to indicate that carrion is part of its com- 
mon diet. Wherever this bird is found to congregate it 
leaves evidence of its food habits by the ejections from 
its mouth of long pellets of partially digested food. 
The seashore, however, is less plentifully dotted with 
these pellets during the summer than in the winter. 
Food is more plentiful inland in the warm months, 
therefore fewer crows are obliged to seek the beaches; 
moreover, at this time the pellets quickly crumble into 
pieces. Freezing weather causes them to retain their 
shape. As these cylindrical objects are sometimes as 
large around and over half as long as one's finger, they 
give an interesting clew to the extremely varied bill of 
fare of the animal. The seeds of sundry plants are 
common constituents, and often these are of a bitter- 
sweet, and even poisonous, variety; but in addition to 
these, there is apt to be present in considerable quan- 
tities the bones of fishes and of frogs or other small 
four-footed animals, the hard parts of crustaceans, 
shells of clams and mussels, periwinkles and numerous 
small mollusks, and not infrequently one comes across 
the wing cases of beetles and other portions of insect 
armor. 

That the crow should become so integral a part of 
the shore life as is the gull, is not surprising. The 
opportunities this region offers to such an indiscrim- 



146 Dwellers of the Sea and Shore 

inating palate are quite obvious. But what is it that 
attracts the other land birds which we see winging their 
way hither and yon over the burning sands? Here is 
the swallow; with its familiar headlong swoop it passes 
close over our heads. Here, also, is the ubiquitous 
sparrow, the robin, the meadow lark, the pipit, and the 
myrtle warbler, none of which is a carrion eater, or 
known to show a preference for sea food. Yet these, 
beside many other distinctly land forms, are as common 
to the seashore as they are to their native woods and 
fields. 

The secret of their presence lies in their food habits. 
Most of them are insect eaters; and few places in the 
world are more prolific of insect life than that line of 
plant remains and other organic debris which marks 
the tidal heights. 

While the scavenger work of the seashore is per- 
formed largely by beach fleas, the little amphipod 
crustaceans Orchestia and Talitrus, terrestrial animals 
having the same food habits, are vigorously disputing 
their province. The number of insect species is not 
large, but in numbers of individuals the proportions 
are enormous. Those actively engaged in reducing the 
jetsam are principally flesh flies (Sarcophagus) , car- 
rion beetles (Necrophorus) , and Staphylinid beetles. 
Associated with these, however, is a tribe of parasitic 
and predatory prowlers whose important business it is 
to hold this prolific horde in check. Even worms — 
mostly Enchytraeids — are represented here; and occa- 
sionally birds which are neither strictly scavengers nor 
eaters of flesh are to be seen picking over the heaps for 
tasteful tidbits. 



Feathers and Feelers 



147 



Seating ourselves in the shade of a thatch clump, 
better to observe the industrious folk about us, our 
inactivity is almost immediately productive of fruitful 
results, but of a kind not exactly agreeable. With 
irritating persistency a large green-eyed fly attempts to 
settle upon some vulnerable part of our body. We 
make haste, however, to drive it away as soon as we 




A STAPHYLIXID, OR SCAVENGER BEETLE. THIS INSECT LIVES ON THE DECAYING 
MATTER AT THE HIGH-TIDE MARK. 



recognize it. For it is Tabanus cos talis, and its painful 
drill is something to be avoided. Notwithstanding that 
Tabanus is a true fly, or Dipteron, and is gifted with a 
powerful pair of wings that enables it to roam wher- 
ever it may list, this species is rarely found elsewhere 
than in the neighborhood of the sea. Its larval life 
is spent in the rich, muddy soil of salt marshes, where 
it feeds only on decaying plant remains. At this period 



148 



Dwellers of the Sea and Shore 



it is a simple semitransparent lethargic tube of liquid 
contents, and to see it thus is to witness a strange con- 
trast to the splendid, tawny, emerald-eyed creature 
which it later becomes. 

Look, there goes Eristalis, pursued by the robber fly 




ROBBER FLY ATTACKING ITS PREY 



(Erax rufibarbus). Whatever advantages the first- 
named fly may have derived from its beelike disguise, 
the imposture surely does not stand it in good stead 
now; for the bloodthirsty assailant will as readily at- 
tack a genuine sting bearer as one which obviously is 
not. Other winged assassins pass. To flies, wasps, 
and beetles, there w 7 ould seem no end. 



Feathers and Feelers 149 

Even the ground has its quota of killers. These are 
chiefly spiders whose nimbleness of foot gives them an 
additional advantage when seeking a hasty refuge in 
the tops of reeds or other shore plants at every in- 
coming tide. There is, however, an air-breathing crea- 
ture here among the ground dwellers that is submerged 
regularly — often for hours at a time — during the 
periods of high water. The insect so distinguished is 
the larva of the tiger beetle known to science as Cicin- 
dela dor salts. 

Now the grub of Cicindela is worthy of our atten- 
tion. For the seashore naturalist, it has an especial 
interest in the fact of its being one of the very few 
insects of the shore which are not known to occur any- 
where else ; its individuality, though, would commend it 
to any one's consideration. 

But where shall we look for this lethal larva? Not 
in the vegetal debris; its soft, unprotected body makes 
it too easy a prey for others thus to expose itself. The 
truth is, its only safe resort is in the ground. Its bur- 
row is quite numerous, as is testified by small holes that 
perforate the surface, and is a vertical shaft some six 
inches deep with a fairly even diameter of the size of 
a slate pencil. This home Cicindela never leaves for a 
moment, until the time of its metamorphosis, when it 
emerges as a swift-flying beetle. How does it capture 
its food? Well, if our watch be persevering, we shall 
see an exhibition of its singular method. 

In the meantime it is to be observed that the grub 
is now T here in sight. This is due to its extreme timidity. 
So cautious is it that our slightest movement is sufficient 
to make it remain for some time in hiding. Presently, 



150 Dwellers of the Sea and Shore 

however, our immobile vigilance is rewarded: the top 
of a flat, hideous head appears at the entrance of a 
burrow. It is hard to say which is the more striking 
about this glossy black countenance suddenly thrust into 
view, the formidable sicklelike jaws or the fixed pair 
of double-orbed eyes that glisten like tiny jet beads. 
These latter organs are so arranged that one part of 
the pair is pointed to the front and the other part to 
the rear, thus enabling the larva to see in all directions 
without moving its head. A few short bristles shine 
about the eyes and fringe the outlines of the face, 
enhancing the savage aspect of the larva. More than 
this is not observable at present. The creature remains 
within its shaft with its head blocking the entrance com- 
pletely and in such a manner that it is on a level with 
the ledge. Indeed, as it now presents itself, it is not 
difficult to detect; but those stubby hairs are worn for 
no idle purpose, and I have seen them more often than 
not so encumbered with adhering grains of sand or 
other particles that to novice eyes the animal would 
readily pass as part of the surrounding soil. In this 
position it awaits its prey with a patience that would 
far outlast our own, did not chance bring an abrupt 
and early close to the monotonous affair. 

A young isopod {Idotea metalltca) about the size of 
an apple seed makes its way over the sand. On what 
business it is bent and where its destination may be is 
not clear, but its course lies almost directly over the 
larva's lair. The little crustacean does not differ 
greatly from its land relative, the common u sow bug" 
found under damp, decaying wood or under stones and 
in other dark, moist places, except that it is longer and 



Feathers and Feelers 15 I 

flatter and is covered with a coat of bright bluish green 
that shimmers with a metallic luster. It is a swimmer, 
but on dry land its mode of progression is virtually the 
same as its well-known cousin; that is to say, it moves 
at a fairly rapid pace. However, it does not move too 
fast for our Cicindela. When it gets barely within a 
quarter of an inch of that living trap, there is a blur, 
and with astonishing suddenness both the isopod and 
the grub vanish utterly from sight. Where they have 
disappeared is, of course, not hard to guess. Yet so 
quickly did the larva work that the eye has taken in 
little of what actually happened to the isopod or the 
extraordinary maneuver by which it was seized. 

To establish this clearly, therefore, let us resort to 
a ruse. But as this is the last that will be seen to-day 
of this particular individual, it will be necessary to 
employ our wits at another burrow, of which there are 
plenty. 

First a fly or some other small insect must be ob- 
tained. This is but a matter of a moment. A dead 
marsh miller lying near by suits the purpose exactly. 
Then, breaking oft a dry reed, we fasten a fine thread 
at the tip. At the free end of the thread a noose is 
made and drawn around the fore body of the moth. 
The result, in short, is a miniature fishing pole and line 
baited and ready for use. Thus equipped, we establish 
ourselves at a likely spot and wait. Our subject soon 
appears at the top of a convenient hole, and with a 
cautious turn of the wrist the dangling corpse is lowered 
over the lurking larva's head. Snap! The swinging 
bait is struck so forcibly that the impact nearly tears it 
loose. The sharp-pointed pincers, however, close with 



152 Dwellers of the Sea and Shore 

deadly precision on the body of the moth, and there is 
a strong, swift tug as the grub attempts to haul its prey 
down into the shaft. But this movement is checked by 
the thread; whereupon the animal, perceiving almost 
immediately that something unusual restrains its effort, 
loosens its hold and withdraws like a flash into its 
retreat; yet not too soon for us to take in certain details. 
The brief interval of time that the grub clings to the 
miller reveals the fact that when engaged in its oper- 
ations it retains a firm grip on the walls of its shaft. 
Moreover, in so doing, it strikes with an upward thrust 
of its head accompanied by a sudden lengthening of its 
body which carries the fore parts and a portion of the 
abdomen well clear of the hole. This "jack-in-the-box" 
performance is accomplished, however, not so much by 
a telescoping of the body as would easily appear, but 
is largely achieved through its peculiar configuration. 
If our sight be keen enough it will have been evident 
that in retracting its body the grub, after a manner of 
speaking, doubled up on itself, by reason of the S-like 
shape in which it is roughly bent. 

Now let us dig out the animal to see if anything more 
is to be learned on this score. Carefully removing the 
sand at one side of the shaft, we discover as we go 
deeper that the latter is of a uniform character and 
without any turns. Here we have a departure from the 
bore of most sand-dwelling beetles. Generally their 
gallery has a sharp curve that becomes horizontal near 
the top. The advantage that that construction offers 
in keeping the loose, dry, shifting sand from filling up 
the burrows is obvious. Nevertheless, our Cicindela 
well knows what it is about in sinking this simple shaft. 



Feathers and Feelers 153 

The nature of the ground indicates at once why a more 
complex burrow is unnecessary. In this instance the 
sand is always moist and more or less closely packed; 
therefore, its tendency to be blown about is reduced to 
a minimum. But what of the water? Although the 
grub need not provide against the hazards of the wind, 
it is clear that it must guard itself against the silting 
action of the waves. If we linger here long enough, 
the animal will show us how it overcomes this little 
difficulty. Still, as a considerable portion of our time 
has already been consumed in following its present be- 
havior, it may be well to anticipate by explaining that 
it plugs up the entrance with sand just before the tide 
comes in. How it becomes aware of the time for ap- 
proaching high water is a mystery. Yet this perform- 
ance is as periodic as the flood. Within the space of 
an hour or more preceding every rise, it seals its hole 
as regularly as though it watched a tidal clock. 

The question here arises as to how the larva over- 
comes being drowned in its narrow cell. This is an- 
swered in our examination of the burrow itself. As we 
dig into the porous sand, a noticeable difference is ap- 
parent in the texture of that portion forming the wall. 
Instead of falling away loosely like the neighboring 
material, the grains that surround the shaft come apart 
in clumps. This means that they are bound together 
with a sort of cement. Closer inspection with a glass 
does, in fact, show this to be the case; furthermore, the 
adhering particles are fixed in a way that makes the 
burrow practically water-tight, but admitting the pene- 
tration of air; the latter feature being of a decided ad- 
vantage to the animal in its long winter sleep. It is 



154 Dwellers of the Sea and Shore 

patent, therefore, that the periodic plugging of the en' 
trance serves not merely to keep the drifting sand out 
when inundation occurs, but at the same time also to 
keep in the necessary oxygen to breathe. 

When the larva is turned up at the bottom of the 
burrow, it proves to be a quite abject and helpless in- 
dividual. Its length is not more than an inch; and as 
it attempts to escape its efforts may best be described as 
a fast crawl rather than a run, for its legs seem to be 
set somewhat closely together under its short thorax, 
and as it moves over the ground it is obliged to trail 
along a cumbersome hind body. The hard armor that 
encases its head extends over the greater part of the 
fore body, but the abdomen is soft and vulnerable, and 
its pale waxlike hue is relieved by markings on the 
upper part of each segment, making a triple row ex- 
tending along the back. The segments are seven in 
number. They are well defined, and from the sides of 
each projects a little clump of short bristles. But the 
most remarkable of the animal's appendages is to be 
found on the fifth segment. This part of its anatomy 
is slightly enlarged, and viewed from the side a pro- 
nounced hump occurs, accentuating the already crooked 
curves of the creature's body. At the peak of this 
hump — that is, on the highest point of the back — two 
stout, sharp hooks, one sixteenth of an inch long, are 
set with their points turned upward. These are placed 
one on each side of the middle line that marks its 
length, and they in turn are encircled at the base with 
bristling hairs. 

Although it may not strike one immediately that the 
bristles on the segments are used for climbing up and 



Feathers and Feelers 155 

down the shaft, one need not hesitate to decide the 
function of the hooks. In view of what we have 
already seen of the grub's habits, does not their position 
and appearance attest plainly that their purpose is for 
maintaining an anchorage in its hole w T hen thrusting out 




LARVA OF THE TIGER BEETLE. 



its head to seize its prey? Furthermore, one can well 
imagine w T hat would take place when it happens to 
catch a tartar, so to speak, if some device did not pre- 
vent it from being dragged from its retreat. 

This is all that the little larva of Cicindela has to 
show us for the present. If we wish to inquire further 
into its history, it will be necessary to raise it in the 
laboratory where under controlled conditions the prog- 



156 Dwellers of the Sea and Shore 

ress of events can be watched with closer attention than 
is possible in the open. There subsequent details, to- 
gether with what can be learned from the adult in its 
natural environment, will give a complete life history 
something like this : The adult female tiger beetle, 
who is provided with a strong egg-laying drill, bores a 
hole in the soil with this instrument and lays a single 
egg. She is easily distinguished from the male, for the 
latter has the sixth segment broadly notched under- 
neath so as to expose the seventh segment, which is 
invisible in the female; moreover, the first three tarsal 
joints on his front legs are very broad and bear a heavy 
coat of down on the under side. The female punctures 
the packed sand about fifty times, leaving an egg at the 
bottom of every hole. Two or three weeks later a grub 
hatches, and the little pit dug by the mother is ample 
enough to hold it; but as it grows, it enlarges its home, 
all the time going deeper and continually consolidating 
the walls. Its growth, of course, is like that of all 
other insects, a process which is closely bound up with 
the molting, or shedding of the skin. When this event 
is about to occur, the larva seals the entrance to its 
shaft, and goes to the bottom, remaining there until 
the change has taken place. For three years its life is 
spent in the ground. Throughout each winter it hiber- 
nates, closing its shaft for this purpose in the early 
autumn ; it does not reopen it again until the middle of 
the following spring. Very shortly after its third and 
last disappearance, however, it changes to the pupal 
form. But this chrysalis stage, during which it retains 
its hooks and develops leglike processes from the four 
segments in front of them, to keep it out of contact with 



Feathers and Feelers 157 

the walls of its cjII, is of brief duration. In the same 
autumn that it closes its door for the last time, it makes 
a complete transformation from a groveling grub to 
a perfect beetle. But the now winged tiger, instead of 
emerging at once from its lair, goes into a long winter 
sleep, and does not awaken until the warm and balmy 
air of May arouses it from its lethargy; whereupon it 
digs its way through the sand that blocks the shaft, 
finding itself finally at the surface. Here it proceeds to 
clean itself. As it rids its feelers and other appendages 
of particles of clinging dirt, the metallic sheen of its 
armor becomes resplendent. Its body underneath and 
over the head and thorax is a deep bronze green. Its 
elytra are mottled with blotches of creamy buff; and it 
occasionally lifts them to give its wings a flick in the 
genial sunshine. Like the larva, it has a pair of terrible 
jaws. In repose they are crossed; and, as the inner 
edge of each sickle is provided with several strong, 
sharp teeth, it is easy to see with what deadly efficiency 
the tiger beetle can work. The possession of this 
weapon gives it a sort of courageous confidence even 
in respect to humans; for if it be flushed it will run for 
a short distance and then fly just out of reach to face 
boldly the pursuer upon alighting. 

We will here leave Cicindela engaged in its oper- 
ations preliminary to taking its maiden flight. To fol- 
low it farther would be to witness a life of further 
slaughter, but add nothing essentially of interest 
therein — unless, perhaps, it be that it is double brooded 
and also hibernates in the perfect or adult stage : prob- 
abilities which are founded on more than a mere sus- 
picion, but which are not known to be certainly true. 



158 Dwellers of the Sea and Shore 




Feathers and Feelers 159 

Still, notwithstanding the murderous instinct that 
makes the behavior of this animal not altogether a 
pleasant feature of its life, it constitutes itself by the 
very nature of that instinct one of our best friends; for 
in preying on other creatures it kills off scores of insects 
which are injurious to us in many ways. 



PART TWO 
THE TIDE POOL 



Chapter X 

FLOWERLIKE FORMS AND FANTASIES 

From out of the past comes a memory of a wonder 
world. I am standing at the edge of a pool on a sunlit 
shore whose dank, glistening sands bespeak the out- 
ward running of a recent tide. The day is young. 
Shortening shadows of strange plant growths lie blue- 
black and sharp on a watery floor; the air is still and 
cool; the only sound is a faint murmur rising from the 
distant washing of a gentle surf. A feeling of be- 
wilderment possesses me. The glassy surface of the 
tide pool, reflecting the brilliant azure of the sky, 
smites the eye with a violent glare, but in the trans- 
parent fulgor, fantastic forms present themselves to my 
startled gaze. I see a forest of fairy trees, fernlike 
glades of shimmering green, and a garden graced with 
filmy fronds of a delicate pink. Moving shapes I see, 
some without color and, so it seems, without substance; 
but many shine resplendent from mystic grottoes, or 
glide about like glittering jewels of living light. . . . 
Yes, form, color, and weight are here; though to my 
enchanted vision all realities become ethereal — the 
loveliness, the transcendent beauty of the scene is over- 
whelming. And as I look into the mysterious depths 
of this magic mirror, all about me has the semblance 
of a dream. . . . 

163 



164 Dwellers of the Sea and Shore 

Such was the impression produced by my first ac- 
quaintance with a tide pool. At the time of this expe- 
rience, nothing whatever was known to me of the nature 
or the identity of the various plants and animals which 
inhabit the seashore. My interest in nature, always 
keen, had hitherto been excited only by such of its 
aspects as are ordinarily familiar to the inland dweller. 
It is true that those contacts were fraught with an un- 
deniable charm. Many a ravishing hour had I spent 
watching some woodland watercourse with its divers 
wonders; indeed, I have often been beguiled into lin- 
gering at the margin of some glistening pond to watch 
with awe just the merest living mote. But on none of 
those occasions did my emotions respond to the degree 
that they did on my introduction to the tide pool. Per- 
haps this was because they had always been among the 
common things of life. It was not so much that mar- 
vels did not occur as that it did not occur to me to 
marvel. Alpine villagers, it is said, fail to find the 
same beauties in their region that move the tourist to 
such superlative expressions of delight. The ever- 
present spectacle of those lofty altitudes is unimpressive 
and without novelty, if not without charm, to a people 
born and reared amidst sublime surroundings. My 
own feelings and attitude in regard to the outstanding 
features of my terrestrial haunts were, doubtless, of a 
sort like this. Then for the first time I saw the sublime 
aspect of nature as it exists only in the sea. I was like 
one lost in a delectable land of illusion. But there was 
no illusion: I had acquired a newer vision; and from 
that moment I have never looked upon living things in 



Flozvertike Forms and Fantasies 165 

quite the same light as I had been prone to look upon 
them before. . . . 

A later and closer acquaintanceship with things 
marine, naturally, has dissolved much that was mysteri- 
ous to me on my initial meeting; nevertheless, this fuller 
familiarity has in no wise tended to diminish their ear- 
lier charms. Seldom do I venture along the shore with- 
out encountering some feature, not necessarily novel or 
strange, yet sufficiently impressive to awaken a respon- 
sive thrill. It must be confessed, however, that the 
waters of tide pools are more fertile of interest and in- 
cident in this respect than any other region of the shore. 

As Harbor Beach is graced with a large and particu- 
larly attractive example of one of these natural marine 
aquaria, needless to say it surrenders to me many 
secrets of the sea. In the shallow water of this ex- 
pansive basin (it is two or more acres) are often 
found, congregating throughout their proper seasons, 
representatives of nearly every type of life peculiar to 
these latitudes. Here are found the forms that line 
the high-water mark as well as those w r hich range the 
deeper levels. For not infrequently is some strange 
straggler from the outer reaches caught unawares and 
left imprisoned by the retreating tide, unable to escape 
until the next succeeding flood. Sponges, too, swept in 
from darker and cooler depths, continue to grow with- 
out perceptible restraint in the genial currents of their 
newer habitat. 

Such a one is the finger sponge (Chalinopsilla 
oculata), a dull orange-red individual with compressed 
fingerlike branches that look like lobes of melting 



1 66 Dwellers of the Sea and Shore 

copper. And then there is its paler cousin (C arhus- 
cula), standing about six inches high, whose delicate 
and finer textured branches of tawny gray grow more 
slender but in greater profusion. Some sponges re- 
semble crumbs of bread; others spread themselves in 
irregular golden masses over the fronds of seaweeds 
or the surfaces of stones. These latter generally first 
find their way here as fragments. Soon or late, how- 
ever, some of these fragments drift into contact and 
coalesce, forming a single but larger and perfect unit. 
Still, of all the immigrants, the boring sponge (Cliona 
sulphur ea) has the most striking habits. It is a light 
cream yellow in color and usually grows on the dead 
shells of the oyster and hard clam, though it some- 
times settles on living shells to the great irritation 
of the animal within. It honeycombs these shells 
with galleries by absorption, wherein it establishes it- 
self, showing only its wartlike prominences through 
little perforations about one eighth of an inch in diam- 
eter that riddle the surface of the valves. In time the 
dead shell is completely disintegrated by the work of 
this persistent borer, but the living mollusk, although 
hard put to prevent this disaster to itself, manages 
to delay if not effectually resist these encroachments 
by the constant secretion of new lime over the parts 
that are penetrated by the sponge. 

But the sponge population of the tide pool is by no 
means composed entirely of immigrants. A community 
long established herein also holds its own. The bril- 
liant orange-red incrusting sponge (Microciona pro- 
lifera), spreading itself in a velvety, tangled mass over 
shells and stones, is a conspicuous example. Less color- 



Flowerlike Forms and Fantasies 167 

fill but equally diverting is the lovely little urn sponge 
(Grantia ciliata). This is a particularly favorable 
type in which to observe the way in which all these ani- 
mals work. If a specimen be placed in a dish of sea 
water, to which a trace of carmine is added, it will be 
seen that the coloring matter held in suspension is 




TUBE SPONGE. A NON-CALCA*EOUS SPONGE. 

sucked through the sievelike pores on the creature's 
sides and expelled in a steady stream through the large 
opening that punctures the top. 

I have referred to the sponges as animals; for that 
in truth is what they are. Aristotle was the first to find 
this out. So, you see, I am not setting forth a fact that 
is particularly new. Yet, in spite of the age-old knowl- 
edge of their identity, there is a prevailing impression 



1 68 Dwellers of the Sea and Shore 

that sponges are plants. This misconception no doubt 
arises from the appearance of those which are in com- 
mercial use. Such sponges, however, are only the 
horny skeletons which in the living animals were com- 
pletely covered with a soft tissue of cells. Even in life, 
they are by no means typical of the group in general. 
For sponges are not only extremely variable in size and 
color; they are also found to grow in a vast variety of 
forms. Some species are so small that they are scarcely 
visible to the naked eye; others grow to such propor- 
tions that their dimensions are only to be measured in 
feet. Again, they range from masses so indefinite in 
outline as to appear like monstrous aberrations, to sym- 
metrical structures of exquisite shapeliness. Neverthe- 
less, the fibrous framework (spongin) of the common 
commercial sponge identifies it as belonging to the Non- 
Calcarea, one of the three classes into which all of these 
animals are divided. The skeleton of those sponges 
belonging to the Calcarea differ in being composed of 
mineral spicules (lime) or a combination of lime and 
spongin. This flinty material gives these individuals 
a hard and rigid character. It should be noted, how- 
ever, that among the calcareous sponges some odd ex- 
amples exist whose skeletons consist wholly or nearly 
so of particles of sand. 

Although the sponges are undoubtedly animals, they 
are very low ones. Indeed, they stand near the foot 
of the ladder that symbolizes the evolution of the 
many-celled organisms. There are many other animals 
which are still lower, but they consist of a single cell. 
The sponges, however, are only a step higher, for, 
although their bodies are composed of an aggrega- 



Flowerlike Forms and Fantasies 169 

tion of cells, they have not so far progressed as to 
acquire a stomach or anything resembling the special- 
ized organs that distinguish other multicellular crea- 
tures. It is on account of their low organization that 
they may be cut into pieces without killing the indi- 
vidual, for each piece will continue to live and grow; 
by the same token, certain members of the same species 
are enabled to coalesce when coming into contact. 

As all animals must eat in order to live and grow, 
the individual sponge, notwithstanding its having no 
mouth or stomach, manages this important business 
in a very efficient way. And although utterly inca- 
pable of locomotion, it captures its food in a manner 
no less adroit than that of the most active swimmer. 
To arrive at an understanding of how this is done, let 
us look more closely into its structure. 

In the living animal, the organic parts — that is, those 
parts which do not comprise the framework — are made 
up of a soft jellylike tissue consisting of three different 
layers of cells. The outside layer, which is virtually 
the skin, is composed of flat cells, and is called the 
ectoderm. The middle layer, known as the mesoderm, 
makes up the main mass of the body, and it is the 
function of these cells, which are of various shapes 
and kinds, to form the framework and take part in the 
reproduction and digestion. The internal layer, or 
endoderm, is an arrangement of cylindrical cells, each 
one of which has at its exposed end a cup, or collar, that 
encircles the base of a freely lashing flagellate hair. 
Now these thread cells (choanocytes) , so-called, liter- 
ally line the walls of the many locks, or chambers, in 
the canal system that traverses the sponge, and it is they 



170 Dwellers of the Sea and Shore 

that capture the minute plants and animals which pass 
in through the pores with the circulating water. But 
please understand — it is not the cilia, or hairs, that 
catch the food; their office is merely to create the cur- 
rents which keep the water moving, a condition main- 
tained by their constant vibration; they both take in 
their food and eject the waste products of digestion 
through the circular orifice within the collar. Thus, in 
fine, the sponge works something like this : Through 
the innumerable fine pores that cover the outside of the 
animal, the water is strained of its coarser particles of 
floating food and the finer material is carried through 
incurrent canals into ciliated sacs or chambers, the cells 
of which select and absorb the suitable ingredients; 
thence the streaming atoms are diverted into the large 
channels and pass out through craterlike vents called 
oscula. In proportion to the pores, the oscula are few 
in number; in fact, it is due to the porous structure of 
sponges that they have received the scientific name 
Porifera. 

The sponges are singular in having no natural ene- 
mies — unless we humans in our commercial exploita- 
tions of these animals can be included in this category. 
But even here our attention is confined only to the 
genus Spongia; and we make some effort to compensate 
for their reduction by artificial propagation. Living 
sponges are cut into pieces, and these are planted in the 
most suitable situations favoring their growth. They 
grow rapidly, attaining a marketable size within a year. 
The commercial sponges of this hemisphere are all 
taken from Florida waters, and off the shores of the 
Bahamas and the West Indies in depths of less than 



Flowerlike Forms and Fantasies 171 

thirty feet. The finest sponges in the world are those 
from the fisheries of the Mediterranean and the Red 
seas. 

Natural reproduction in these creatures is carried 
on in two ways. In the sexual method, which is the 
most common, eggs and sperms are formed in the mes- 
oderm. The fertilized eggs escape as rounded ciliated 
larvse which, on finding a favorable bottom, immedi- 
ately attach themselves; given to growing rapidly, they 
soon become mature individuals. Sponges reproduce 
asexually by budding. The buds in some instances re- 
main attached to the parent and continue to grow; 
usually, however, they drop off and drift away to begin 
life anew. 

In another chapter we have seen that certain sea- 
weeds, the corallines, bear a close resemblance to the 
corals; there are, on the other hand, animals which 
have every appearance of being seaweeds. Their plant- 
like character is even more marked than that of the 
sponges. These are the fixed hydroids ; and although 
the ordinary eye would never associate them with jelly- 
fishes, their relationship, as a matter of fact, is not far 
removed, for they belong to the coelenterates, or 
polyps. Indeed, all the animals which are now known 
as coelenterates were at one time called zoophytes, a 
term meaning "animal plants, " and suggested by their 
likeness to plant forms. And it is the class Hydrozoa 
of the coelenterates in which are included all the hy- 
droids, both fixed and free-floating. 

The fixed hydroids differ from the free-floating 
forms in that they are invariably colonies of associated 
animals which remain attached to a common, base 



172 Dwellers of the Sea and Shore 

throughout their communal life. That is to say, like 
plants they spend their entire adult life on the spot 
where they originally started to grow. It is true, in this 
respect they do not differ from the sponges, but so much 
more pronounced is their plantlike appearance that the 
comparison here is quite to the point. Some there are 
which liberate swimming bells. It is for this reason 
that hydroids often have been called the nurses of 
jellyfishes. 

Throughout the summer months the fixed hydroids 
are well represented in my tide pool. However, of the 
four main groups, or genera, into which these animals 
are divided, tubularians, campanularians, sertularians, 
and plurnularians, the sertularians are the most abun- 
dant. Hanging like frosted fringes from the fronds of 
seaweeds, can be seen the silver sertularian (Sertularia 
argentea) ; and the sea cypress (S. cnpressina), a 
species somewhat similar, with its arched and drooping 
branches, forms funereal groves over shells and stones; 
but the commonest and in one sense the most curious is 
the creeping sea oak (S. pumilla) . This hydroid criss- 
crosses its silken stems in such profusion that it some- 
times hides completely the rocks or seaweeds on which 
it grows. From the tangled web, there rise at close 
intervals slender, upright stalks about an inch in height 
adorned with zigzag branches. 

But how is one to determine their animal nature and 
avoid confusing them with seaweeds, which they so ob- 
viously simulate? Very easily. A strong glass, how- 
ever, must be used for the purpose. All hydroids, in 
fact, can be studied to advantage only under the lens. 
Few sertularians, as a rule, reach higher than a foot, 



Flowerlike Forms and Fantasies 173 

and their branches are so fine as sometimes to be almost 
invisible. When magnified, a branch will be found to 
consist of a horny shell or tube divided into more or 
less regular internodes. In some species this tubular 
branch contains a single canal throughout its length; in 
others, it may contain several. These canals contain 
living substance, the horny exterior being only a sup- 
port and protection. But the most striking thing that 
greets the eye are the flowerlike forms arranged alter- 
nately along opposite sides of the internodes, and which 
constitute the individual animals themselves. Each one 
is an anemonelike creature — in this case, called the 
hydranth — held in a transparent cup of amber, over 
the brim of which it spreads a spray of sixteen tentacles, 
silvery petallike processes of gossamer fineness. These 
are arranged in a single whorl around a conical, or 
dome-shaped, proboscis having in its center a tiny aper- 
ture, the mouth. The cup that holds the hydranth is 
known as the hydrotheca, and in sertularians this is 
almost always set close to its supporting branch without 
a connecting stem, or pedicel. On the hydrothecal rim 
is a hinged structure which w T orks like a trapdoor when 
the hydranth retracts, closing after the animal to pro- 
tect it from harm. A diaphragm forms the floor of the 
cup, and through a hole in this passes part of the body 
of the hydranth, making it continuous with the other 
hundreds of hydranths which compose the colony. 

At occasional points along the branches, larger urn- 
shaped bodies are to be seen. These are the repro- 
ductive organs {gonosomes) , and with rare exceptions 
the entire colony will contain sex organs of one kind 
only — which is to say, the colony is either male or 



174 Dwellers of the Sea and Shore 

female. In sertularians, sexual reproduction is a proc- 
ess not greatly unlike what we have observed in the 
case of the seaweeds. The sperm cells stream forth 
into the water in countless numbers. On reaching the 
female colonies, they pass through a perforation in the 
top of the gonangia, seeking the eggs. Only a few 
are fortunate in finding the ova, however, whereupon 
fertilization is immediately effected, to be followed 
later by the development of the embryos. Eventually 
these embryos grow into ciliated larvae which, on being 
liberated, swim to some substantial support and pro- 
ceed forthwith to start new colonies. 

The campanularian hydroids, to which reference has 
been made, are many of them similar in naked-eye 
aspect to the sertularians. Put they differ quite notice- 
ably under the glass. Take Clytea (Clytea poterium) 
for example. What in most sertularians is a horny cup 
set close to the branch on which it is borne, is in the 
case of this animal a stemmed goblet of crystal trans- 
parency. The goblet, bell-shaped and open at the top, 
is smooth around the rim and without the angularities 
or modulations commonly found in campanularian hy- 
drothecae; but the stem is faintly ringed throughout its 
length, giving the merest suggestion of an ornamental 
pattern — in short, the simplicity of its design makes it 
a fitting support to so chaste a chalice. The hydranth 
— but how shall I describe the hydranth ? Every goblet 
contains a cluster of scintillant tentacles; yet so feeble 
is the light they reflect that they look like the pale glow- 
ings of ghostly stars. Somewhat like the sertularian, 
the sea oak, this hydroid is a creeping form. The 
main stem runs rootlike over the stones or seaweed to 



Flower like Forms and Fantasies 175 

which it is attached, and this gives rise to the upright 
pedicels bearing the nutritive and the reproductive or- 
gans, or zooids. In Obelia (Obelia commissural^) , 
however, a campanularian generally found in company 
with Clytia, the form of growth differs considerably. 
Here the main stem rises to a height of six inches; 
it carries branches spirally arranged around its axis, and 
these in turn subdivide into other and shorter members. 
The ultimate branches are in reality the ringed pedicels 
of twelve-sided cups. The cups are bell-shaped but 
slightly incurved. Indeed, the campanularians get their 
name from the characteristic shape of the hydrotheca, 
for campanula, from which the name is derived, is liter- 
ally u a little bell." The reproductive zooids, larger 
and vaselike, are on short, ringed pedicels occupying 
the angles of the branches. 

Now, although the campanularians just described 
have a superficial resemblance, even under the glass, to 
the sertularians, it is here in their outw r ard aspect that 
their similarity ceases. Their life histories are totally 
different. In the life cycle of these hydroids is ex- 
hibited that peculiar phenomenon know T n as alternation 
of generation (metagenesis) , two different forms of 
individuals in one species, or, to put it another way, one 
kind of individual in two separate and distinct forms. 
Specifically, Clytia and Obelia are at one stage of their 
lives fixed hydroids, or polyps; at another, jellyfishes. 

Here is how it comes about. The reproductive 
zooids of these animals, unlike those of the sertularians, 
produce neither eggs nor sperms; instead, they contain 
little stacks of saucer-shaped medusae, or jellyfishes, 
which, in their form of attachment to one another by 



176 Dwellers of the Sea and Shore 

the middle of the convex side, recalls what we have 
observed in another place regarding the strobila of the 
large jellyfishes. When, at maturity, the cover of the 
zooid ruptures, the tiny jellyfishes are liberated. From 
the inside center of a swimming bell thus set free de- 
pends the stomach of the creature, having at its outer 
end a four-cornered mouth. Diverging from the point 
where the stomach is attached are four tubular canals 
in the bell which are continuous with a circular canal 
running around the rim. This is usually a conspicuous 
feature, and often serves as an aid to identification. 

When a hydroid is in the jellyfish stage, it may be 
said to have reached the highest point in its develop- 
ment; for it is only in the mature medusa that sexual 
reproduction occurs. The eggs are pear-shaped ciliated 
bodies, which are dispersed by the parent medusae at 
the end of summer ; they swim or drift around until they 
reach a favorable anchorage ; whereupon they grow 
into hydroid colonies which in turn give rise to other 
jellyfishes in the following spring. Some medusae, in 
addition to their egg-bearing capacity, can reproduce 
by budding, producing smaller individuals on the 
stomach or on the rim of the bell. Moreover, not all 
campanularians are positively known to be of the above 
described type. Many of these hydroids have not yet 
been observed to bear medusa cups; nor can all the un- 
doubted hydroid medusae be identified with the polyp 
colonies from whence they came. What is more, some 
live always in the medusa state, having no colonial 
existence whatever. 

The plumularians, as the name would indicate, are 
featherlike hydroids — at least they were when this 



Flowerlike Forms and Fantasies 177 

name was first applied. But now, since our knowledge 
of these animals has been vastly extended, a quite 
numerous group of individuals has been included among 
them which have no resemblance to a feather. For in- 
stance, there is one (Antennularia antennina) which 
often appears in my tide pool, that is decidedly weed- 
like; it grows in dense clusters of sparsely branched up- 
right stems to a height of eight or more inches, and is 
by no means prepossessing. However, among those 
forms which do bear out their characteristic name, are 
the most beautiful of all fixed hydroids. Such is the sea 
plume {Aglaophemia struthioides) , a species found on 
the Pacific coast. It has a striking likeness to a min- 
iature ostrich plume, and the rich, colorful tones of 
some individuals make them even more attractive than 
the object for which they are named. This hydroid, 
like many other plumularians, has the zooid cups ar- 
ranged only on one side of their supporting branch. 
The cups are without pedicels, or stems. 

But there is one thing in which plumularians agree, 
and it is the distinctive feature that now identifies all 
members of the group regardless of their superficial 
aspects. This is their stinging organs known as 
nematophores. Whereas, in the other fixed hydroids 
that we have considered, the tentacles of the hydranth 
are the only organs bearing stinging cells, in these crea- 
tures the nematophores are additional members in- 
vested with these deadly darts. These are bodies of 
sundry shapes, the external shell being generally tubular 
or trumpet-shaped, containing a smgle tentacular finger 
capable of great extension. They are variously situated 
along the internodes and sometimes on the sides of the 



178 Dwellers of the Sea and Shore 

zooid cups themselves, compared with which they are 
greatly inferior. Their purpose is not definitely known, 
but on occasion they can function as weapons either of 
capture or of defense. It is supposed, however, by 
many naturalists, that the nematophores are merely 
degenerate zooids. Reproduction is of the same type 
as that of the sertularians; there is no medusa stage. 
In the genus Antennularia, however, exists the unusual 
instance of both male and female zooids in a single 
colony. 

In a well-shaded spot at the edge of the tide pool, 
where the overhanging mud bank exposes the mussel- 
laden roots of the thatch, I often find a hydroid which 
is incomparably more like a flowering plant than any 
other species of my acquaintance. Not only does this 
apply to the polyps, but the colony as a w T hole has every 
appearance of a floral bouquet. It grows on the shells 
of the mussels, yet not infrequently it attaches itself to 
the dead stems and roots that are imbedded in the side 
of the bank. Quite dense are its clusters, and fully two 
inches high; and its amber-tinted stems are terminated 
by the prettiest of pink hydranths. It is one of the 
tubularians (Thamnocnidia spectabilis) , and so like a 
certain real plant is it, with its delicate stalks and starry 
zooids, that it is known everywhere as the passion 
flower of the sea. 

I think it hardly necessary to point out here that the 
flowerlike zooids, as is the case with other hydroids, are 
the nutritive parts, and that their stinging properties, 
besides assisting in the capture of small organisms, are 
of considerable help in the animal's defense. But, let 
me say, this pretty polyp, powerful as it is in its way, 



Flozcerlike Forms and Fantasies 



179 



has, nevertheless, some irresistible enemies. On one 
occasion I observed a roving herd of fiddler crabs de- 
scend into the water of the pool and strip these diminu- 
tive gardens bare of every branch and blossom. But 
their greatest foe in this place undoubtedly is the hermit 
crab; when this hungry prowler finds them out he will 




clava; a colony of tubularian hydroids (enlarged.) 



spend hours in plucking oft the clusters — plucking off 
many more, in fact, than he can possibly consume. 

Now in regard to the hermit crab and its appetite, 
an odd sight sometimes presents itself. Often one of 
these creatures will be seen searching assiduously for 
food while the shell which it bears is literally covered 
with living hydroids. Yet, though its craving may be 
ever so keen, it will not touch them. These hydroids, 
too, are tubularians, and are generally of the genus 



180 Dwellers of the Sea and Shore 

Hydractinia. They form a soft mosslike covering, 
usually of a whitish or pinkish color — the lighter-hued 
colonies being male, and the darker-hued, female — and 
are very seldom found growing elsewhere than on the 
shells of hermit crabs. Here, then, we find that re- 




hydractinia; a colony of tubularian hydroids. (photograph made of the 
living animals growing on a shell occupied by a hermit crab j 
greatly enlarged.) 



markable instance known as commensalism, a term 
which, freely defined, means "dining at the same table. " 
But in this case, as indeed is the case with most true 
commensal animals, they do more than merely dine 
together ; they really render each other a service. That 
is to say, this sort of association is formed for mutual 
benefit. The tubularians, beside the concealment they 



Flowerlike Forms and Fantasies 1 8 1 

may offer to the crab, are effective against its enemies 
with their stinging weapons of defense. The hermit 
crab reciprocates by carrying the colony about to places 
most likely to be plentiful with food; a favor enhanced 
by the fact that the polyps are also assured of better 
oxygenation. 

When a colony of Hydractinia is examined closely, 
the individual polyps will be found to rise from a horny, 
rootlike network creeping over the surface of the shell. 
It will further be observed that the zooids are of three 
entirely different kinds: a nutritive member carrying a 
crown of tentacles; a second slender individual without 
tentacles but well armed with stinging cells, and a 
shorter stalk on which a small cluster of ovoid bodies 
is attached near the top. These latter are the gono- 
phores. Hydractinia has no jellyfish stage; the eggs 
develop into swimming larvae which seek the shell of 
some other hermit crab than that on which they were 
born, and there commence another colony. 

The characteristic feature that distinguishes tubu- 
larians from other hydroids is in their long slender 
zooid-bearing stems. These in some instances reach a 
length of ten or more inches; often they are branched. 
The zooids ordinarily have two rings of tentacles en- 
circling the mouth. In many species, however, the 
mouth is raised on a prominence, or proboscis; and not 
infrequently reproductive zooids will be attached be- 
tween the two rows of tentacles or just below the outer 
fringe. In no tubularian does a horny hydrotheca 
cover the hydranth. 

Such free-swimming colonies of hydroids as this pool 
affords are few if not relatively rare. This is not to 



1 82 Dwellers of the Sea and Shore 

imply that there exists a scarcity of these forms. They 
are, on the contrary, very numerous. Their usual 
haunts, however, are the more open spaces of the sea. 
Southern and tropical waters, particularly, are prolific 
of these wandering creatures. Once in a while some of 
these warm-water dwellers drift to these northern lati- 
tudes with the Gulf Stream, eventually finding their 
way to this shore. Of these floating wanderers, one 
form is especially worthy of our attention here, because 
of all the free-swimming hydroids it is the most beau- 
tiful and the most famous — and the most dangerous. 

Physalia arethusa, or Portuguese man-of-war, as this 
notorious coelenterate is called, floats on the surface of 
the water — a resplendent, fairy craft of faint purple 
and rose. The hull, or body, of this marvelous ship is 
a bubblelike bag about five inches long roughly resem- 
bling a dirigible balloon; and it carries a crest, or sail, 
that can be raised or lowered before the wind. The 
bag is filled with air, and from beneath trails a cluster 
of brilliant blue streamers which sometimes are nearly 
one hundred feet in length. In addition, there depends 
a mass of flask-shaped bodies, or feeding zooids, and 
some that look like miniature bunches of grapes, the 
reproductive zooids. 

The attractive tentacles of Physalia, as in the case of 
the large jellyfishes, are covered with stinging cells; but 
in this instance they are more poisonous and para- 
lyzing. A strange thing — is it not? — that such an ex- 
quisite creature should possess so terrible a power. No 
fish of ordinary size can escape when coming in contact 
with this alluring snare. In its deceptive mazes sea 
turtles weighing twenty pounds or more are, in spite 



Flowerlike Forms and Fantasies 183 

of their scaly armor and leathery hide, caught and 
benumbed and rendered utterly helpless. Nay, the dan- 
ger that lurks in that deadly touch makes the man-of- 
war a fearful animal to encounter by even the human 
swimmer. 

Yet, notwithstanding the deadly nature of the ten- 
tacles, they harbor, unharmed, certain little fishes which 
swim throughout the treacherous toils with perfect 
freedom and unconcern. This, you will admit, is truly 
remarkable. How much more so, then, is the fact that 
these constant companions of Physalia are of the exact 
color — a bright, pretty blue — as that of the monstrous 
members among which they make their home ! 



Chapter XI 
CAMOUFLAGE 

In the color resemblance of the fishes that follow 
Physalia, we have touched upon a circumstance which 
leads us now to consider some important and funda- 
mental advantages possessed by certain animals of the 
seashore in their struggle for existence. I refer to 
those aggressive and protective endowments, apart 
from distinct organs of offense and defense, which are 
usually known as mimicry, masking, deceptive colora- 
tion, or by some term of similar significance. 

The dense population of the shore makes competi- 
tion exceedingly keen. Everything that is edible has 
scores of hungry claimants; this applies to the larger 
living animals as well as to the most trifling bit of 
organic food. Now, as one half literally subsists on 
the other half, it is obvious that any device which will 
enable the possessors the better to obtain something 
to eat or to avoid being eaten, will promote the welfare 
of the species as effectively as that of the individual. 
No one can seriously study the conditions that prevail 
in this area without becoming early aware of the fact 
that, notwithstanding the enormous prolificacy which 
obtains here, the balance of life is maintained at a 
somewhat critical point. Even among the dominant 

184 



Camouflage 185 

forms, the line that lies between their present suprem- 
acy and total extinction is by no means a broad one. 
Many mighty multitudes are holding their own in the 
tremendous struggle merely by virtue of some appar- 
ently insignificant feature in form or color. 

Such advantageous features as swiftness of move- 
ment or unusual strength, of course, contribute largely 
to an animal's ability to make a living; but even these, 
in many instances, would be quite useless were it not 
within the power of the animal to render its presence 
unperceived when approaching its prey. In so doing it 
seeks to identify itself with its surroundings by one of 
three ways: by actual concealment, or hiding; by dis- 
guising its appearance w T ith a covering of materials 
miscellaneous in origin — that is, by masking; or, as is 
most commonly the case, it relies on its natural color 
or markings or peculiar shape to keep it inconspicuous. 
Thus it will be seen that the resorts of the killers in 
deceiving their victims are as ingenious as they are 
varied. Human enterprise is hardly less distinguished. 
When, in the recent war, we went into the business of 
butchering each other, w T e took a hint from the animals, 
and, as our borrowed methods needed a distinctive 
name, the word "camouflage" came into popular use. 
Although science has not yet adopted this very useful 
term, its employment here will not be out of place. 

Camouflage, then, may also serve the purpose of 
protection as well as aggression. It is clear, moreover, 
that the capacity of a creature to conceal itself from its 
enemies is of an importance not inferior to that of 
making itself invisible to its prey. 

Fishes are classic examples of natural camouflage. 



1 86 Dwellers of the Sea and Shore 

Their hues and markings almost invariably harmonize 
with their native haunts, and a great many species are 
capable of changing their colors momentarily to con- 
form with the prevailing tints or tones of various locali- 
ties. As nearly all of them are white along the under 
surface of the body, it is not unlikely that to their ene- 
mies which view them from below they would be con- 
fused with the light above; and to the birds and other 
enemies over them, their markings and coloration 
doubtless make their forms quite indistinct. In the 
perpetual darkness of the deep sea, camouflage is un- 
necessary. As a consequence, we find the fishes there 
unmarked, their entire bodies being an inky violet in 
color, below as well as above. In truth, to say nothing 
of the birds, such as slaty blue gulls and terns, w T hich 
are colored like the sea, there are throughout every 
group of marine inhabitants — mollusks, crustaceans, 
echinoderms, worms, etc. — abundant instances wherein 
the perpetuation of the species is unquestionably due to 
protective or aggressive resemblances. 

However, it is not my purpose to range the entire 
ocean for specific instances or to recite even a rep- 
resentative list of examples. Nor is it necessary. My 
present object will be fully attained, I think, without 
venturing beyond the comparatively narrow limits of 
my tide pool. At any rate, let us see w T hat it holds 
for us. 

This briny basin is so situated that when the tide 
is low its broadest expanse is separated from the waters 
of the harbor by a reef of gravel and sand. Owing to 
the shifting nature of this material, the outer shore of 
the pool is continually changing by the tidal action; 



Camouflage 187 

consequently, few plants find a footing here. And for 
a considerable area along the margin, the clear, shallow- 
depths also appear quite barren of animal life — at least 
it would thus appear to the inexperienced. Save for a 
few small snails clustered in the furrows of the rippled 
floor or an occasional hermit crab cautiously roaming 
about, there would probably be little else to attract the 
notice of the average passer-by; yet unknown to him 
he would be the focus of many pairs of eyes belonging 
to creatures much larger than these. If he unsuspect- 
ingly steps into the water at this place, surprising evi- 
dence of this fact will manifest itself. Almost from 
under his feet will be a scurrying of shadowy forms 
slightly smaller than his hand, in length and breadth. 
Let him follow one of these creatures in its flight and 
determine exactly where it stops, and he will discover 
that he is utterly unable to locate it. So completely has 
it effaced itself from view that he begins to doubt his 
sense of seeing. With a hand net he may perhaps suc- 
ceed in capturing one of these elusive shadows, but not 
so long as it is content to remain at rest on the bottom. 
It must first be startled from its place and then be 
caught on the leap, so to speak. 

After which it will prove to be a fish; a flounder, in 
fact, or flatfish (Pseudopleuronectes americanus). A 
very unusual fish it is, also; and in more ways than 
would appear at firsthand. It swims and lies flat on 
one side, the lower side being white, or colorless, while 
the upper side is grained and mottled and presents an 
appearance identical with the coarse, sandy floor of its 
haunts. These imitative markings are not confined to 
the body alone; they extend over the fins and tail. 



i88 



Dwellers of the Sea and Shore 



Here, in a word, is the real reason why the flatfish is 
indistinguishable when it is motionless. The most 
striking of its adaptative features, however, is the posi- 
tion of its eyes. In the common fishes familiar to 
everybody these organs, like those of the higher ani- 
mals, are situated one on each side of a middle line 
dividing the right and left half of the body. But the 



?5» 






ROCK CRAB CONCEALING ITSELF IX THE SAXD. THE ANIMAL IS IX THE CEXTER OF 
THE PICTURE. THE FORE PART OF ITS BODY AXD THE EXDS OF ITS CLAWS ARE 
THE OXLY PORTIOXS EXPOSED. 



flounder is almost a freak; its eyes are both on one side 
of its head; in other words, on that side of its body 
which it keeps uppermost. When one considers, more- 
over, that this creature is hatched as a transparent 
fish, swimming vertically in the water, with an eye on 
each side, the foregoing circumstances seem all the 
more striking. Nevertheless, it should be observed 
that these changes are not more marvelous than the 



Camouflage 189 

postembryonic metamorphoses by nearly all of the 
other animals of the sea. Indeed, I may add that the 
more metamorphosis is studied, the more it becomes 
divested of its aspect of marvel, though its absorbing 
interest, of course, never diminishes; for reduced to its 
simplest terms, metamorphosis is development. Those 
features which excite our wonder usually do so because 
of the extraordinary or strange contrasts they present; 
that is to say, development, always gradual and orderly 
in its course, is sometimes, however, revealed only as 
if it were an occasional occurrence, consequently giving 
the impression that its progress is marked by sudden 
transitions from one peculiar phase to another. As I 
have said, our flatfish swims vertically when hatched. 
Soon it starts to rest itself obliquely on the bottom, and 
the eye on the lower side commences to turn upward. 
As growth continues, this eye gradually moves with its 
socket around the forehead accompanied by a twisting 
of the skull until eventually both eyes and both sockets 
are more or less approximated on the upper side. By 
this time the fish has assumed its characteristic flat 
position. But the end is not yet. The full-grown flat- 
fish is an inhabitant of the deeper and darker waters; 
it is only the young and immature animal which I find 
frequenting the shallow bottom of my tide pool. There- 
fore, before its growth will have been finally completed, 
it will have changed its bright sand-colored coat to 
one of a hue more somber and in keeping with the sur- 
roundings of its adult home. 

Now the capacity for color resemblance that inheres 
in our flounder is clearly of a decided advantage. Were 
it not so endowed, it would become the prey of count- 



190 Dwellers of the Sea and Shore 

less larger creatures; for it is a harmless and rather 
feeble swimmer, subsisting only on small mollusks, 
worms, and crustaceans, and its sole means of protec- 
tion is by escaping observation. Notwithstanding its 
apparent immunity, it has several harassing enemies 
which make its existence anything but serene. Pres- 
ently we shall have occasion to see one type of these 
killers at work. 

The whole of the question of camouflage among 
animals is as yet imperfectly understood. It is known, 
certainly, that deceptive resemblance confers an enor- 
mous degree of protection to those forms so distin- 
guished and which are too weak to resist their superiors. 
But what is the answer in regard to those which are 
equally defenseless and which by no stretch of the 
imagination can be considered inconspicuous? After 
eliminating those instances where inedibility, unusual 
prolificacy, agility, and kindred conditions may be fac- 
tors, there yet remain cases in which the species seem 
to thrive without the apparent protection afforded the 
majority. These matters, doubtless, will some day be 
cleared up when our general knowledge of the con- 
ditions of life is more complete. 

There has been much nonsense written on this sub- 
ject. It has been seriously suggested that deceptive 
resemblance h an exercise of the will on the part of 
the animal; although it is only fair to add that no com- 
petent naturalist nowadays holds this to be the case. 
Nor should the learner who perchance has read some 
of the older overenthusiastic literature entertain this 
belief. In what way, for instance, the flatfish has come 
to acquire and exercise its remarkable property of de- 



Camouflage 191 

ception is even now not agreed on by naturalists, but 
not one of them asserts volition or intent to be a factor. 
That animals may adopt certain habits, and that these 
habits may tend to bring about actions in long-contin- 
ued circumstances which accentuate or reenforce those 
deceptive features of form and color, is patent to any 
one who has a mind to study the matter; but that this 
is the result of reason, it does not at all follow. Rather, 
it is instinctive or reflex ; and these inherent qualities are 
the result of slow and gradual growths through a long 
line of ancestors. And here too, by the way, is a broad 
hint regarding the colors of those creatures which do 
not seemingly find them useful. It is not improbable 
that the color markings of many present-day marine 
animals exist solely as the result of heredity; they were 
handed down by ancestors who, living under different 
conditions, found them directly and decidedly beneficial. 
The objections that may be urged against volition in 
the case of color resemblance cannot be maintained in 
regard to that method of camouflage known as mask- 
ing, except, perhaps, only insofar as instinct is con- 
cerned. Strangely, the most celebrated instance of this 
form of disguise is not, as one would expect, among the 
fishes, but is among the crustaceans, a group far less 
advanced in general intelligence. The crustaceans thus 
eminently distinguished are the long-legged spider 
crabs, a tribe of creatures so resourceful that they 
have often been honored with a place at the head of 
the entire group. When collecting seaweeds in my 
pool, I have several times come across the natives 
of this vicinity {e.g. Libinia dubia ) L. emarginata) 
in a most unexpected manner. These animals have 



192 Dwellers of the Sea and Shore 

evolved the habit of planting on their bristly backs 
all sorts of marine vegetation and low forms of animal 
life such as hydroids and sponges. The result is that 
they are sometimes so completely hidden by these 
growths that their presence is indistinguishable in nor- 
mal situations. In gathering material, therefore, I 
have been deceived into attempts to appropriate the 
private property of these animals; and my efforts to 
detach some likely-looking specimen from its base 
brought a pair of puissant pincers to bear upon my 
hand. These crabs are sluggish in their movements, 
which perhaps accounts for their habit of disguising 
themselves, and although some individuals have legs 
that spread over a foot they succeed in masking their 
appearance very effectively. 

The plants and other growths which they gather for 
masking purposes seem to be selected with an extraor- 
dinary degree of acumen. They will transplant only 
such organisms as will not suffer permanent injury by 
being torn apart. That the growths on their carapaces 
are placed there by intention and do not affix themselves 
spontaneously, and that the spider crabs are quite as 
able to denude as to adorn themselves, becomes readily 
obvious if we place one in a tank or other environment 
which contains masking material of a different kind or 
color than that already covering the animal. If the 
creature is masked with colors that contrast with its 
surroundings, it will remove its coat and replace it with 
one in harmony with the new locality. In making this 
change, the crab laboriously picks off with one of its 
claws whatever colors are not in keeping with its situa- 
tion, the chelipeds being well adapted by their length 



Camouflage 193 

and by the flexibility of their joints to perform this 
operation. Then the animal selects a suitable object 
and holds the broken portion to the appendages of its 
mouth where it is manipulated and covered with a secre- 
tion of some adhesive substance, after which it is car- 
ried with an overhand movement to the back and at- 
tached. This is continually repeated until within a few 
hours the spider crab once more resembles a miniature 
garden. In addition to the cement they use, some crabs 
are provided with hooks and barbs on their backs, 
which aid in holding fast the transplanted organisms. 

It may be of further interest to note that among the 
spider crabs are found the largest crustaceans in the 
world. These are the giant Macrochiras of Japan, 
full-grown individuals of which are said to have a leg 
spread measuring fifteen feet. 

The invisibility that the dwellers of the tide pool 
achieve by color combinations, strange shapes, or mask- 
ing would seem to be perfect, at least to human eyes — 
and there is no good reason to believe that the lower 
animals have a better vision or even one to equal ours. 
Yet, perfect as is this achievement, it is as nothing, 
in a way of speaking, compared with that of some crea- 
tures in this place, which dispense entirely with such 
shifts. The glass prawn (Palcemonetes vulgaris) is 
such a one. This crustacean frequently crowds the 
pool in great numbers, especially in the fall; but so 
transparent is it that shoals containing hundreds 
could pass within the observer's reach without his 
once suspecting it. Only by holding it to the light 
in a glass of water can its form be seen with any 
degree of distinctness. Its body is about one and 



194 Dwellers of the Sea and Shore 

one-half inches long and it has antennae that equal 
it in length. Its legs are remarkably slender and 
fragile and seem almost too delicate to support even 
so buoyant a body as the prawn's appears to be; the 
animal is, nevertheless, a good crawler and gets its 
food by this means, either on the bottom or on the 
fronds of seaweeds. 

As a matter of fact, all prawns, though capable 
swimmers and given to migration, are sedentary in 
their habits, and the majority of species, like many 
other sedentary animals, are protectively camouflaged. 
They may be uniformly colored in sundry shades of 
red, brown, or green, or they may be marked by various 
patterns of color. These varicolored individuals are 
usually found among seaweeds which they closely re- 
semble : the blotched and the barred forms, for instance, 
are frequenters of the larger and coarser weeds, and 
the lined forms live among the finely branched and 
feathery growths. There is evidence that these dif- 
ferent color patterns may be acquired during the 
growth of the animal; that is, a young prawn reared 
among finely branched seaweeds will become lined, 
while another kept in a tank containing coarse vege- 
tation will in time acquire bars or blotches. Even adult 
specimens have been observed to change their color 
after a few days when placed among plants of a dif- 
ferent hue, their pattern, however, remaining the 
same. But here is something still more peculiar : if one 
of these prawns be put into a white dish, or if kept in 
the dark, it becomes nearly colorless, and it does so 
within a very short time. This it accomplishes by a 
contraction of its pigment cells, or chromatophores, the 



Camouflage 195 

substance from these diffusing into the fluids of the 
body and giving the animal a transparent tint of deli- 
cate blue. As this is a phase which- under natural con- 
ditions is assumed at nighttime, it is interesting to note 
that chromatophores of prawns kept in the dark con- 
tinue for several days periodically to expand and con- 
tract, the rhythmic movements of the pigments being 
regulated in a manner corresponding to the alternation 
of day and night. 

The habit of hiding involves none of the freatures of 
camouflage that we have considered, but it is apparent 
that the safety from attack which weak animals find in 
this form of protection is of considerable consequence 
in their struggle for existence. Very early in my con- 
tact with seashore life the significance of this method 
of concealment was strongly impressed upon me. The 
incident which I have in mind beside revealing animal 
behavior, introduced me to that very curious creature, 
the squid, an animal hitherto known to me only through 
pictures and writings. 

At that time I was quite unfamiliar with many of the 
tide-pool inhabitants, and the most commonplace of 
them would hold my wondering attention for hours. 
A periwinkle making its way over a frond of seaweed, 
a little horseshoe crab plowing through the mud or a 
sea worm slowly extending itself out of the slime, were 
novel and thrilling affairs. A circumstance, too, of no 
mean magnitude was the molting of a crustacean. Now, 
a lady crab, in the slow process of shedding its skin, 
had once engaged my curiosity for a considerable 
while when eventually I realized by the rising water 
that the incoming tide had reached the pool and that 



196 Dwellers of the Sea and Shore 

further observation would soon be impossible. I wis 
about to wade in to get the animal and place it in a 
small pool on a higher level when it promptly disap- 
peared with an oblique backward movement into the 
sand. In spite of the fact that my acquaintance with 
its ways was limited, this sudden action, coming at the 
end of a long period of lethargy, and the further fact 




LADY CRAB. 



that I had as yet made no effort to disturb the creature, 
struck me at the moment as being somewhat queer. 
At the same time an equally puzzling performance 
took place on the part of some small fishes hovering 
in the vicinity. These — it was later that I learned 
they were Mummichogs (Fundulus majalis) — darted 
to the bottom and buried themselves, too, out of 
sight. A suspicion crossed my mind. I had known 



Camouflage 197 

birds to take precipitately to cover on the appear- 
ance of a hawk in the neighborhood, and this, no 
doubt, led me to infer that something of a similar 
nature had caused the crab and fishes to conceal 
themselves. I was not wrong. On looking around, a 
sight greeted me that took away my breath. Several 
yards distant a school of squids was approaching. The 
animals did not number over a dozen, but the turmoil of 
sand that followed in their wake and the swift dartings 
backward and forward of some, made their numbers 
appear actually greater. The cause of the silty turmoil 
was soon made clear. The squids were evidently on the 
hunt for prey. As they proceeded, now and then an 
individual would descend to the floor and feel over the 
surface with a pair of long flexible tentacles. Suddenly 
these organs would encounter some living object lying 
unseen on the sand, and a short struggle would ensue in 
which a cloud of silt and sand was raised. A squid 
would then emerge into view, holding in its monstrous 
tentacles the unresisting form of a flatfish, and swim 
away, closely accompanied by a couple of its less for- 
tunate and jealous companions, a hazy reddish trail 
meanwhile marking its course : the blood of its victim 
which had been bitten through the back. 



Chapter XII 
CURIOUS CREATURES 

The squid and its allies, the octopus and cuttlefish, 
have long held an evil reputation. Old books — many 
of them dating back to the last two centuries — contain 
pictures and descriptions of huge devilfishes over- 
whelming and capsizing ships with their tentacles. To 
these creatures romancers have ever been prone to 
ascribe a nature and capacity frightful in the extreme. 
Nor are modern fictionists insensible to the fascination 
and dread that an artful account of their exploits can 
inspire. So they often use them in their tales as an aid 
to excite the imagination. And these colored accounts 
of the nature and capacity of devilfishes, though less 
exaggerated than those of older writers, succeed in 
fostering in the popular mind an impression wholly at 
variance with what are the actual facts. Indeed, as a 
consequence, they are generally conceived to be the 
most fearful of all invertebrate animals. 

Marine naturalists give us a quite different version 
of the activities of these creatures, and from their im- 
passioned reports we learn that the devilfishes are not 
so black as they are painted; moreover, it is revealed 
that the leading trait they display in their behavior 
toward humans is either docility or fear. 

198 



Curious Creatures 199 

Devilfishes, or cephalopods, are highly organized 
mollusks, being very close relatives of clams, snails, 
slugs, etc., and they are primarily distinguished by their 
tentacular sucker arms arranged in a radial manner on 
the head around the region of the mouth. They are 
carnivorous, or flesh-eating, and subsist chiefly on 
fishes and crustaceans. There is some evidence that 
certain squids are at least part vegetarian in their diet, 
for several six-foot specimens captured off Catalina 
Island, California, were found to have their stomachs 
full of seaweed. 

Squids range in size from the little sepiolas of about 
an inch long to the giant Architeuthis, the largest 
known invertebrate, which measures, it is said, nearly 
fifty feet over the entire length of its body. These 
large creatures are all inhabitants of deep waters, and 
have never been seen alive near the shore. They are 
probably very scarce, as few have ever been discovered; 
even of these, none was in a perfect condition when 
found, owing to the violence of storms or the attacks 
of whales. Sperm whales live almost entirely on cepha- 
lopods, which they destroy in countless numbers in their 
excursions through the open sea. The common squids 
of my vicinity do not attain to more than a foot and a 
half in length. They are rovers and generally travel in 
schools, following shoals of young fishes or minnows. 
Often, however, a lone raider will stalk its prey. And 
in so doing, it presents some remarkable color changes. 
This property of changing its color, shared by all 
cephalopods, is due to the chromatophores covering the 
surface of its body. The principle on which the pig- 
ment cells work is somewhat like that obtaining in the 



200 



Dwellers of the Sea and Shore 




LOLIGO; A SQUID. (PHOTOGRAPH TAKEN ON THE BOTTOM OF A TIDE POOL.) 

iris of the human eye. When the colorless animal is 
in the act of changing to a darker shade, a dilation of 
these minute organs exposes a pigmented area; each 



Curious Creatures 201 

chromatophore, like an enlarging freckle, spreads out 
until it coalesces with its neighbor. These changes — 
from white to deep mottled brown or full purple, or the 
reverse — can be produced instantly and can be re- 
stricted to different areas of the body, thus enabling it 
to simulate a pebbly bottom or other environment with 
more or less fidelity. Few things are more startling to 
the novice than the rapid flashes of color that pass 
over these creatures. At one moment it may be of a 
deep tone contrasting strongly with some shell-covered 
floor, then suddenly it becomes almost invisible by turn- 
ing a ghostly white, and will slink away like a specter 
of its former self. The mode of progression used by 
the squid is no less curious than its appearance. Its 
body may roughly be compared to a common force 
pump wherein water enters at one aperture and is ex- 
pelled at another. It is the force of the water directed 
through the "spout," or siphon, located just below the 
head at the base of the tentacles, that propels the ani- 
mal. This force is produced by contractions of the 
mantle, a loose saclike envelope wherein are enclosed 
the stomach and other vital organs. Usually the squid 
swims with its so-called tail foremost, but it can reverse 
its course without changing the direction of its body 
simply by turning its flexible siphon the opposite way. 
In addition to their effective color changes, all ceph- 
alopods, with the exception of the single genus Nauti- 
lus, possess a unique organ, called the ink bag, with 
which they can render themselves invisible. This organ 
produces an effect similar to the smoke screen employed 
by naval vessels in combat. When one of these animals 
is irritated or pursued, it ejects a black substance 



202 



Dwellers of the Sea and Shore 



that clouds the water and disconcerts or confuses its 
enemies. 

Although the name "devilfish" is by many indis- 
criminately applied to the squid, the octopus, and the 
cuttlefish — and even to many creatures outside of this 
group — its use in literature seems to be restricted to 
the octopus; at least this appears to be the devilfish 




EGGS OF THE SQUID, ATTACHED TO A CLUMP OF RED SEAWEED. EACH OF THE 
CYLINDRICAL OBJECTS IS COMPOSED OF A GROUP OF EGGS NUMBERING MANY 
HUNDREDS. 



described in the majority of stories; which is strange. 
For they have neither the aggressiveness nor the huge 
proportions attained by the squids. It has been ex- 
tremely infrequent that octopi have been found with 
tentacles over ten feet long. And even when large 
individuals are caught they show no disposition to fight 



Carious Creatures 



203 



but invariably make a desperate struggle for liberty. 
Notwithstanding that they have great strength and 
are armed with a powerful weapon in their sharp 
parrotlike beaks, they appear to be unaware of their 




BABY SQUID; JUST HATCHED. (GREATLY ENLARGED.) 

potentially dangerous possession, seeming never to 
attempt using it in their defense. 

An octopus is a timid creature and will usually 
retreat when a human being comes near it, but it is not 
a hard subject to study in its natural habitat if one 
is cautious in one's movements. Like most wild crea- 



204 Dwellers of the Sea and Shore 




OCTOPUS, OR DEVILFISH, 



Curious Creatures 205 

tures they recognize as inimical only objects in motion. 
The difference between a typical octopus and a squid 
may be stated tersely by saying that the first-named has 
eight long tentacles and a short body and the second- 
named has ten short tentacles and a long body. The 
relative lengths of the tentacles in both forms will often 
vary considerably, but their numbers always remain as 
given. It is because of its comparatively long arms, or 
tentacles, that the octopus, no doubt, gets its unsavory 
reputation; these writhing members make it the most 
hideous and gruesome of all living things. The hard, 
stony stare of the creature also adds much to the gen- 
eral impression of horror that attaches to one's sight 
of it; the visual organs of no other animal have the 
ghoulish, terrifying expression that is in the eyes of the 
devilfish. This weirdness is even still further accen- 
tuated by the insinuating, tortuous movement of the 
entire body as it crawls from place to place ; for, unlike 
the squid, it seldom swims when it wants to travel. 
When it does so, however, it employs its siphon and 
also works its way with rhythmic contractions of a w r eb- 
like connecting membrane between the bases of the 
tentacles. For the most part, it remains secreted in 
rocky crevices, there awaiting its unwary prey, but it 
has been seen to dash out of the water for several feet 
and scramble up the dry rocks after a fleeing crab. 
Seldom is there an escape of the victim, whether it be 
fish or crustacean, when once the snaky arm, lined with 
its double row of sucker disks, is shot in its direction; 
despite its struggles, it is quickly pulled up to the sharp 
nippers and dispatched. 

The female octopus is a devoted parent. She usually 



206 Dwellers of the Sea and Shore 

selects for her nest a recess in the rocks below the low- 
tide level, and guards her eggs with all the jealousy of 
a mother hen. The eggs, when first laid, are small oval 
bodies somewhat resembling translucent grains of rice 
growing around a common stalk. Each one is sepa- 
rately attached to the stalk by a short peduncle, the 
whole being not unlike a bunch of tiny white grapes. 
The average number of individual units in the brood 
of a full-grown female is fifty thousand. She aerates 
them frequently by manipulating the clusters with her 
tentacles and directing a current of water upon them 
with her siphon. Only occasionally does she leave the 
lair, and then merely for a short time when it becomes 
necessary to search for food. The brooding period 
lasts for about seven weeks; at the end of which, the 
young hatch soon leave to begin a life free from fur- 
ther maternal care. In appearance the new-hatched 
octopus is greatly unlike the adult; its arms are quite 
undeveloped and decorate the head like a raked crown. 
In the cuttlefish w T e find a cephalopod having most of 
the attributes of the squid. That is to say, it is an 
active swimmer and it has ten arms and a propor- 
tionately long, but somewhat flat, body. All but two 
of its tentacles are relatively short; these two are de- 
void of suckers along their length except on the club- 
shaped enlargement at the ends. They are generally 
kept retracted close to the head and are brought into 
play only in the capture of prey. It is from the ink bag 
of this animal that the India ink and sepia of commerce 
is obtained. This creature is also the source of the 
familiar cuttle "bone" that is given to caged birds. 
Strictly speaking, this object is not a bone but is the 



Curious Creatures 



207 



internal calcareous shell secreted by the cuttlefish. 
Cuttlefishes are abundant in tropical waters; I have 
seen their white shells so thickly strewn on East African 
beaches that it was all but impossible to keep one's eyes 
open in the dazzling glare. The animals are harmless 
and inoffensive to man, and never attain the size of the 
octopus. Yet, so firmly established is the fear of devil- 



• V" 

"V g 

■ 


■ 




BL 


1 ML 1, "'^BKb 


ML/ 


yw 


if 



CUTTLEFISH. 



fishes in general that the most venturesome of a mis- 
informed public will shrink from bathing in waters that 
are know T n to be frequented by these cephalopods. 

Indeed, the universal prejudice against the larger 
cephalopods is maintained in more restricted environ- 
ments. In an actual test made in a marine laboratory 
where an octopus with arms a foot long was confined, 
scores of visitors who passed the tank were asked to 



208 Dwellers of the Sea and Shore 

touch the animal; yet less than two per cent did so, al- 
though in each instance the request was made after 
earnest assurance was given that the devilfish was harm- 
less and would merely squeeze the hand. 

An extraordinary or repellent aspect in a lower ani- 
mal is an almost certain obstacle to its finding any favor 
with the multitude. That beauty or ugliness in any 
creature, as in humans, may often be only skin deep, 
so to say, seems not to be generally considered. To 
the true naturalist, however, no creature is ugly. The 
serious business of his life., removes him from those 
aversions commonly inspired by outward appearances. 
This happy indifference, of course, most persons do not 
share. But they ofttimes regard as forbidding, and 
even unworthy of consideration, many living things 
which a kindly attempt at acquaintanceship would re- 
veal to be prepossessing and genuinely interesting. 

Now, while this is in a deep sense true of that class 
of cephalopods just considered, it applies with special 
significance to a group of animals in no way related to 
them. And this group is the greatest in the animal 
kingdom. It is the worms. Of all the creatures that 
are universally held in aversion, none takes precedence 
over these in popular contempt. Nor is this contempt 
entirely without cause. The unwholesome experience 
of mankind, gained largely through contact with de- 
generate parasitic forms, has done much to create an 
antipathy toward all the other members of the group. 
Nevertheless, there is considerable interest attaching 
to the worms, and a charitable inquiry into their ways 
will amply repay the investigator. By far the greater 
in number, both of species and individuals, are those 



Curious Creatures 209 

which live in salt water. Here is to be found every 
type, from the lowest to the highest, from the most 
abhorrent to the most attractive, and forms which in 
richness, variety, or harmony of color are not surpassed 
even by the exquisite tints of the comb jellies. All 
show marvelous adaptation to their environment, many 
exhibit uncommon ingenuity in the construction of their 
homes, and not a few T betray an intelligence that is 
superior to numberless creatures more highly organized 
than they. In truth, the simple organization of the 
worms when contrasted with the complex life histories 
often prevailing among them, is one of the greatest 
marvels in natural science. So involved is the develop- 
ment of some of the most abundant forms that years 
of patient investigation have not yet determined its 
exact nature. 

Perhaps the strangest puzzles occur among the flat 
worms, the lowest of all worms. There are some 
which begin life as males, but later in life they lose 
their masculine characteristics and become females. 
Others, again, seem to have lost all functions of sex, 
reproducing their kind by dividing into several pieces, 
each piece, after growing into a perfect adult, repeating 
the process. 

The largest of the flat worms, and, for that matter, 
of all worms, are contained in the nemerteans, a class 
characterized principally by the long, narrow, pro- 
trusible proboscis carried by the individuals. A com- 
mon type is the ribbon worm (Meckelia inserts). This 
animal is found in tide pools secreted under stones or 
buried in the sand between the tide marks. Its length 
when full grown is ten feet or more; its breadth is 



210 Dwellers of the Sea and Shore 

about an inch. It is flat, extremely soft, and of a pink 
or flesh color, and in general appearance not greatly 
unlike the article from which it receives its popular 
name. Despite its great length, it is capable of con- 
tracting to less than a yard; but in doing so, it loses its 
flat shape and becomes nearly cylindrical. Although it 
is a most delicate creature, it can burrow with great 
rapidity when escaping from its pursuer. It does this 
with the help of its long proboscis, an organ that is 
also used in determining the location and effecting the 
capture of its prey. The proboscis, by the way, has no 
connection with the alimentary tract; it is an inde- 
pendent structure and is extruded through an opening 
on the top of the body near the forward end. The 
mouth is on the under side, and is capable of engulfing 
creatures of considerable size. In accomplishing this, 
part of the esophagus is thrust out to envelop the ob- 
ject, and it is then withdrawn. 

The ribbon worm lives mostly on worms which it 
finds buried in the sand or mud; although I have fre- 
quently encountered it in the nighttime swimming 
around in the pool, obviously on a predatory hunt. As 
it extends itself with wavelike undulations over the 
stony bottom, its proboscis constantly darts here and 
there among the crevices in search of a victim. Often 
this will prove to be a member of its own species. Like 
most nemerteans it is a cannibal, and will readily de- 
vour those of its kind which are not too large to be 
overcome. Its voracity knows no bounds. Nor is the 
creature exactly discriminating in its quality of food. 
It will eat worms, such as nereids, which grow nu- 
merous spines or bristles. In that, event, these indiges- 



Curious Creatures 211 

tible portions often work their way through the in- 
testinal wall and out of the body; but this is in no wise 
disconcerting to the nemertean, as the punctures heal 
rapidly, leaving it no worse for the experience. 

All nemerteans have the power to regenerate lost 
parts, which enables them to undergo astonishing in- 
juries without fatal results. They can be cut completely 
in two, and the fore body will ultimately grow T into a 




meckelia; the ribbon worm, with proboscis partly extruded. 

new and perfect worm, while the hind body will retain 
its vitality for days before dying. This division of the 
body can be accomplished by the animal itself, and it 
seems sometimes to occur as a natural process. Their 
tendency toward self-mutilation is so great, in fact, that 
they cannot easily be handled; they will often separate 
under the slightest touch. The planarians, a lower 
group of flat worms, possess the power of regeneration 
in an even greater degree. When they are divided not 



212 Dwellers of the Sea and Shore 

into two but several pieces every piece will live and 
function as an adult. If, on the other hand, they merely 
are mutilated instead of cut through, bizarre forms will 
result from this modified tendency to regenerate. 
To exert no more effort in the capture of prey than 




EGGS OF A FLATWORM LAID ON THE GLASS SIDE OF AN AQUARIUM. (ENLARGED.) 

is required in the normal process of breathing, is the 
ultimate in solving the food problem. Yet this very 
thing is accomplished by the serpulids. Scientifically, 
the serpulids are known as tubicolous polychate anne- 
lids. For our purpose, however, it will be sufficient to 
understand them as tube-dwelling segmented, or ringed, 
worms bearing bristles — which means precisely the 



Curious (J features 



213 



same thing. These odd creatures are also very beau- 
tiful; their variegated colors and conspicuous corollate 
gills give them the appearance of delicate flowers. A 
constant circulation of the surrounding water is caused 
by the cilia on the gill filaments, and these currents pro- 
duce a vortex that brings oxygen to the gills, and small 
organisms into its mouth. Serpula, departing from the 



■''".V 


tj^'J^^V^ 


-v3 












>': 


^S&cff^ 


^SM^ : 


* 


■ m . - 


• v. •* •• 




0'^ 




ILHPfVtf. 


B. 





THE MASOX WORM. 



methods of the tube-building mason worm, which con- 
structs its house of agglutinated shell and mineral frag- 
ments, and the comb worm, which cements grains of 
sand together in mosaic fashion to make its free cone- 
shaped shelter, manufactures its own materials. The 
structure is a frail tenement, but one of imposing excel- 
lence. It is a calcareous tube, winding about over small 
stones or dead shells, and is, by some mysterious chem- 
istry of the worm's body, converted from the com- 
pounds of the sea. 



214 Dwellers of the Sea and Shore 

Another instance wherein the gills serve the double 
purpose of supplying the animal with oxygen and food, 
but in a manner considerably different, is in the blood 
worm (Polycirrus exitnius). It is a segmented worm, 
deep crimson in color, and adorning its head is a crown 
of crowded tentacles, or gills, composed of transparent 



flfi^ 









m ■ 



serpula; a tube-building worm, this creature has built its tube on the 

dead shell of a whelk. 



filamentous strands that are continuously contracting 
and expanding. These can be extended to several times 
the length of the animal's body, the latter being about 
three inches long. A pair of shorter, branched gills 
also occur on each segment of the forward half of the 
worm, while the hinder part is bare. In this creature, 
as well as many others of its class, the typical crown of 
appendages that they bear may with equal correctness 



Curious Creatures 



215 



be termed either "tentacles" or "gills," as it is evident 
these are used both for feeding and respiration. 

The blood worm makes its home in the mud where 
it lies buried with nothing but its tentacles showing. 
These ramify in all directions, suddenly shooting out 




POLYCIRRUS; THE BLOOD WORM. 



over and under the surface of the substratum, and 
would be invisible but for the brilliant stream of blood 
pulsating through them. Its food consists of organisms 
which are minute but not necessarily microscopic. 
Sometimes a little Cyclops or a larva of some larger 
crustacean will brush against the tenuous strands; in- 



2i6 Dwellers of the Sea and Shore 

stantly it is arrested in its course and wafted at once 
toward the ever-waiting mouth. 

Highest of all worms are the segmented forms, and 
the highest of these are the wandering, or free-swim- 
ming bristle bearers. And among them are the most 
beautiful. The attractiveness of two types, Aphrodite 
and Nereis, has already been dwelt on in an earlier 
chapter, so that feature needs no further comment 
here. Nereis (X. virens), however, merits attention 
for other reasons quite as much as for her beauty. She 
is easily reared in the indoor aquarium. The activities 
of few other inmates are more interesting to watch than 
are hers. When young the worm will make a nest in 
old shells or under stones; sometimes it will seek a 
frond of Ulva for this purpose. After growing too 
large for such quarters — a length of fifteen inches being 
not uncommon for this animal — she burrows into the 
sand or mud where she builds another. Her retreat 
is a tunnel, the lining of which is composed of an ad- 
hesive mucus that binds the walls. Quite often it is 
built in such a manner that she has egress at either end, 
thus facilitating her escape when pressed by an enemy. 
Notwithstanding that the diameter of the tunnel is 
approximately that of her body, she can turn around 
in it with remarkable ease and rapidity. Here she 
remains hidden throughout the day, seldom venturing 
to extend more than half her length beyond the open- 
ing. She loves the night. It is then that she becomes 
quite active. Leaving her burrow she will wander 
about for hours, and being a fairly fast swimmer, as 
well as an exceedingly graceful one, the distance she 
covers is not inconsiderable. In the tanks of my lab- 



Curious Creatures 2 1 7 

oratory these worms invariably find their way back to 
their nests, but it is quite certain that with the larger 
freedom of their natural habitat, they do not often 
return to their original homes; therefore it would seem 
that Nereis is practically put to the necessity of con- 
structing a new shelter at the end of every jaunt. 

As to the why and wherefore of this propensity for 
nocturnal prowling, the reader should have no difficulty 
in anticipating. It is born of a desire to escape the 
hunger of others as well as to appease her own. Under 
the cover of darkness Nereis eludes the vigilance of 
numerous stronger creatures always on the lookout for 
such a toothsome tidbit as is she. Some of these, in- 
deed, know where she lives and root her out of her 
home. At this business, the flatfish is particularly pro- 
ficient; but probably the greatest enemy of the worm is 
a creature of another kind, Limulus, the horseshoe 
crab, an animal which, molelike in habit, leads an under- 
ground life for the express purpose of feeding on this 
and many other worms. 

Now Nereis herself is a fierce and voracious 
huntress. Although she will eat almost any kind of 
food, plants occasionally included, she is given to the 
capture of living prey. For this purpose she is well 
equipped. Her powerful jaws, hard and horny, are 
very like a pair of serrated sickles. They are set well 
back in the throat, and in bringing these formidable 
weapons into play, she everts her pharynx, much as 
one would turn inside out the finger of a glove; the 
seized prey is then withdrawn into the throat and torn 
apart, the jaws doing the work of a gizzard. Nereis, 
in fact, is possessed of remarkable strength throughout 



218 



Dwellers of the Sea and Shore 



her body, and is no mean antagonist of many larger 
creatures. She will easily overpower any other worm, 
not her species, which is her equal in size. Nor is she 
above destroying the weaker of her own species when 
hunger impels. She has a well-developed head on 



dm, 


1 


' £f:-";. : . f; : ; 





•*w . |p - - , , 


,%|l %'. 





NEREIS, THE SAND WORM, ATTACKING A SMALLER INDIVIDUAL. 



which the eyes, feelers, and other specialized sense 
organs are located. Her eyes are somewhat primitive 
in structure and seem incapable of forming a distinct 
image of surrounding objects; she relies principally on 
her feelers and olfactory organs to detect the proximity 
of her prey. 



Curious Creatures 



219 



Little is known of the habits of the males, except 
that during the breeding season, about the first week 
in July, they swarm the waters in enormous numbers 




JAWS OF THE SAND WORM. 



after sundown. They are a little more than two inches 
in length, and the posterior part of their body is 
bright red and peculiarly modified. They appear to 
be short-lived, for at the close of the swarming period 
they are found dead in hundreds, and are not seen 
again for another year. 



Chapter XIII 
A "LIVING FOSSIL" 

At the northern border of my tide pool, the bottom 
and the neighboring beach lose somewhat of their 
sandy character. The region is paved with the stones 
and pebbles that have been transported here by ancient 
glaciers. Time and tide have done much to wear them 
down, and those which are more exposed are flattened 
in shape owing to cleavage by the frost and other 
natural agencies. They are of various sizes, ranging 
from small waferlike pebbles to an occasional bowlder 
standing as high as my waist. They are of red sand- 
stone and form no part of the native rock that composes 
the foundation of Lond Island. Whence they came 
no one knows. Geologists have made several attempts 
to trace them to their source, but without success. 

Now these stones have an interest all their own, 
apart from the mystery of their origin. If an expert 
blow be given to the laminated edge of one of the slabs, 
it will open after the fashion of a ponderous volume, 
and just as in some long-forgotten tome, wherein is 
sometimes discovered between the ancient leaves the 
stark remains of a flower which bloomed in another 
day, there will likewise be found preserved in the stony 
matrix pretty plants of a former age. Gone, of course, 

220 



A "Living Fossil" 221 

is the actual substance of the originals; many, many 
thousand years have passed since they were resolved 
into the elements from which they were derived ; but the 
outward shapes remain as perfect as when in that far- 
distant time they drifted to the floor of some quiet lake 
or inland sea to become entombed in the hardening silt 
and sand. 

These petrified plants tell an impressive and curious 
story. They tell us that great and important changes 
have occurred on the surface of the earth in its past 
history, changes that occurred not only in the character 
of the land but in the living things which inhabit it as 
well. But most striking, perhaps, is the revelation they 
make in regard to the enormous length of time that the 
changes involved. The years that have passed since 
these forms flourished are reckoned only in millions. 
And yet this duration of time is relatively short when 
compared with the total time that vegetable life has 
existed on this planet; for these particular petrifactions 
are flowering land plants, and in point of time they 
were preceded by other forms whose beginning was so 
remote that the significance of the number of years 
which have since elapsed cannot easily be grasped by 
the ordinary person. 

It is a singular circumstance, however, that so far as 
actual proof exists in the records of the rocks the origin 
of animal life was immeasurably distant to that of the 
plants. The fossils of animals are found in rocks much 
older than those in which any plant remains appear. 
But this may be simpler than it seems. The most an- 
cient plants were undoubtedly the soft vegetation of the 
sea, and, therefore, they were not so easily preserved 



222 Dwellers of the Sea and Shore 




AN ANCIENT ANIMAL OF THE SEASHORE. (TRILOBITE FOSSIL.) 



A "Living Fossil" 



223 



as were the hard coverings that prevailed among some 
of their contemporary creatures. 

One of those creatures was the trilobite. And, in- 
deed, its enduring remains are among the oldest of all 
undoubted and definite organisms found in the primor- 
dial rocks. The general form of the trilobite is not 




SOW BUGS. 



unlike that of the familiar terrestrial isopod crustacean 
called the u sow bug." After the manner of the sow bug 
it was able to roll itself up into a ball, and in this posi- 
tion its fossil has often been found. Formerly the two 
were thought to be related, but, notwithstanding cer- 
tain of its crustacean characteristics, the trilobite has 
in recent years been classified w T ith the Arachnida, a 
group including the spiders and scorpions. The truth 



224 Dwellers of the Sea and Shore 

is that the systematic place of this ancient creature has 
always been a debatable one, many naturalists holding 
quite opposite opinions as to its position among animals. 
It gets its name from the three prominent lobes, or 
regions, into which the body is divided : cephalic, tho- 
racic, and abdominal; that is, the regions of the head, 
fore body, and hind body. Although more than five 
hundred species are known, many of them diverging 
widely in structure, they all agree in having a head 
shield more or less crescentic in shape; and, except in 
the case of a few T blind forms, this head shield bears a 
pair of large compound eyes. Succeeding the cephalic 
region is a varying number of free segments, each of 
which consists of an arched section flanked by a pair of 
lateral plates. This, the mid-region of the body, is 
terminated by the abdomen, similarly arched, but 
having the segments fused. 

Fossils of the trilobite in which the appendages of 
the under side can be distinctly traced, have been ex- 
ceedingly rare, and only in one genus (Triarthrus) is 
their structure accurately known. In this instance it 
was discovered that each segment of the body carries 
a pair of legs jointed to the lateral plates. In the 
region of the mouth the base of the legs was armed 
with teeth, subserving the purpose of mastication, or 
the reducing of its food. 

The trilobite, no doubt, lived along the seashore 
where it slowly plowed its way in the mud and sand 
after worms and other soft-bodied animals. It prob- 
ably became extinct long before flowering plants made 
their appearance on the land; which is to say, it died 
out about the time the coal beds were formed. The 



A "Living Fossil" 225 

cause of its disappearance is as obscure as that of its 
origin. 

Although the typical trilobite has ceased to exist, 
it has living to-day a relative in the horseshoe crab 
(Limulus polyphemus) , the sole surviving descendant 
of an otherwise extinct group of animals. The life his- 
tory of Limulus is as interesting as it is simple; for in 
the development of this ancient creature is to be found 
one of the most beautiful illustrations of that great 
natural principle which seems to prevail to the effect 
that the ancestral forms are recapitulated in the embry- 
onic and larval stages of the individual. 

The horseshoe crab is found along the whole At- 
lantic coast from Maine to Yucatan. Although far 
less numerous than even a generation ago, it is still 
common enough to be one of the most familiar animals 
of the seashore. Considering for a moment the in- 
creasing scarcity of this creature, it may be stated that 
in recent years mankind has become more and more 
aware of its edible properties and of its value as a soil 
fertilizer. This has resulted in a wholesale and unin- 
telligent slaughter. Naturalists have recorded that as 
late as the year 1856 more than a million horseshoe 
crabs could be seen to come ashore and lav their eggs 
within a single mile along certain sections of the East- 
ern coast. That this abundance nowhere near exists 
to-day is ample testimony that their future is very in- 
secure, and unless some measures are taken to preserve 
them, they will at the present rate of decrease prac- 
tically be exterminated within the time of men now 
living. 

Limulus lives on sandy and muddy shores below the 



226 



Dwellers of the Sea and Shore 




en 

O r 

X 



A "Living Fossil" 227 

low-water mark. The young, however, are often found 
in considerable numbers on the less exposed floor of the 
tide pool, where, molelike, they plow their tortuous 
way through the upper part in pursuit of worms. The 
adult animal when full grown is nearly two and a half 
feet long, and its rounded domelike carapace, or ceph- 
alothorax, is about a foot wide. Half of the length 
is taken up by a slender spinelike tail which is jointed 
to the double-tipped abdomen. The abdomen is one 
rigid piece, and is edged with a row of small spines. 
Viewed from the top, the crescentic outline of the 
creature compares favorably with that of the object 
after which it receives its popular name. The head 
region is strikingly similar to that of the trilobite, even 
to the large compound eyes that are near each side at 
the top. It has another pair of eyes, but these are 
very simple in structure and there is no evidence that 
they are of any use to the creature. They are located 
at the base of the first spine on the middle ridge. 
Indeed, it is very probable that the vision of the horse- 
shoe crab at best is quite crude. Nor is perfect seeing 
in its case essential. In its underground life of dark- 
ness — which is the greater part of its existence — there 
is little necessity for the use of eyes. 

Notwithstanding that Limulus is one of the oldest 
inhabitants of the sea, it is a very clumsy swimmer. 
When it does essay to swim, its efforts are usually re- 
stricted to gliding in an uncertain manner over the 
bottom, by a method of locomotion that is best de- 
scribed as half running and half paddling. This ob- 
servation applies to the adult; when young it manages 
this thing far better. Whatever capacity the horseshoe 



228 Dwellers of the Sea and Shore 

crab has for swimming lies in the leaflike appendages 
under the abdomen. In this respect its walking legs 
are very inefficient, but they are eminently adapted 
to the work they chiefly perform; that is, propelling 
the animal through the sand and mud. If we 
examine the under side of this quaint creature, a 
confusing array of appendages confronts us, but a 
brief though careful inspection will soon familiarize 
them. Taking first the head region, we find this 
forms a great cavity, or bowl, in which are contained 
six pairs of chelate legs (having claws), and one pair 
of broad horny plates called the operculum. The first 
pair of legs is small and lies just in front of the mouth. 
In the male the second pair of claws is larger than in 
the female. The sixth pair of legs is composed of 
large, strong segments like the four pairs immediately 
preceding it, but its claws are of a diminutive size. 
These latter legs are further peculiar in that they are 
modified near the ends into a whorl of three flat or 
oarlike expansions which spread out in use, thus apply- 
ing greater surface to the yielding sand. The base of 
this pair of legs has another process termed the 
flabellum. With the exception of the first pair, all the 
legs are set at an angle to the body which enables the 
animal to bring the greatest power or purchase to bear 
in forcing its way through the substratum. But there 
is one extraordinary feature of the legs that will strike 
the most casual observer; for in no other living animal 
is there a similar adaptation. Nor for the particular 
purpose it subserves, is there one quite so singular. 
Like its ancient forebear, the trilobite, the horseshoe 
crab carries its teeth on its legs. Excepting the first 



A "Living Fossil" 22<) 

and sixth pair, the base of each of the others is set 
with sharp, bristling spines, which, like jaws, macerate 
or tear the food before it is swallowed. 

The operculum acts as a covering for the abdominal 
appendages, of which there are five pairs and which 
resemble it in form. These support the gills. The 
pairs overlap each other to some extent, and each 
appendage is composed of a broad, thin plate having on 
its rear surface large leaflike and membranous folds to 
which are relegated the function of respiration. 

Before proceeding with the development of the 
famous young of Limulus, it may be well for us to 
observe what part the parents play in their destiny. To 
this end, therefore, let us see what the beach has in 
store for us. On my visits there, early in May, when 
the waters of this latitude have lost their intense win- 
tery chill, I find the horseshoe crab making its first 
appearance. Throughout the season of cold, it has 
sought the safety and seclusion afforded by the outer 
floor of the harbor, where it lies dormant, not, it w T ould 
seem, buried underneath, but resting somnolently on 
the bottom. This fact is evidenced by the inordinately 
heavy growth of hydroids, barnacles, and plants which 
cover the carapaces of so many returning migrants: a 
condition that is impossible in an active underground 
life. The little ones of the tide pool, also, have begun 
to show 7 themselves. They have, in fact, never left its 
precincts. With the onset of winter, they dug them- 
selves in on the spot; and now, in common with their 
elders and many other creatures of the land and sea, 
they are awakened by the arrival of warmer w T eather 
into renewed activity. In the quiet enclosure may be 



230 Dwellers of the Sea and Shore 

seen the devious course of many well-marked trails over 
the mud, at one end of which the vigorous worker 
reveals itself by throwing up a miniature cloud of silt 
as it uses its gill plates to sweep the loosened particles 
to the rear. The telltale trails are of various sizes, 
ranging from the breadth of my little finger to the 
width of my hand. 

But most interesting is the behavior of the adults. 
For them I must look elsewhere. On the wide stretch 
of gravel, sand, and comminuted shells that lies between 
the pool and the waters of the harbor, are sundry low 
mounds scattered here and there. They are of the 
usual size and general appearance that would be caused 
by throwing up a shovel full of sand. They are not so 
caused, however; they are produced by mating horse- 
shoe crabs. Each tumulus denotes the presence of a 
pair who, having been stranded here by the falling tide, 
pushed their way underneath partly to make a deposi- 
tory for the eggs, but also ostensibly to conceal them- 
selves. Their efforts to conceal themselves, however, 
are not often successful; they are suggestive of the 
fabled ostrich, since in many instances it is the female 
only who hides her head in the sand. She is the larger 
of the two, and her smaller mate may be seen immedi- 
ately in the rear with both his heavy claws tightly 
gripping the two terminal points of her abdomen. 

The mating couples do not all take advantage of the 
tide to reach this strand. Occasionally a female, seem- 
ingly unable longer to withstand the urgency of mater- 
nal demands, will leave the water when it is low, and 
proceed up the shore, dragging after her an attendant 
male with his hold firmly fixed on her abdominal tips. 



A "Living Fossil" 231 

Sometimes several will follow her. Then occurs a 
strange procession. Each male hangs on to his fellow 
in front while she leads the gang to a suitable spot 
where, after scooping up the sand with her broad head, 
she at once deposits her eggs. The males then cover 
them with milt. Whereupon the party breaks up ; some 
of the members return to the water, some await the 
rising tide. The eggs are some of them later carried 
about by the action of the waves, but the majority soon 
settles into the sand, or in the interstices of the gravel 
to undergo a short — or long, as the case may be — 
period of incubation. 

It may appear from the foregoing incident that my 
previous statement, concerning the probability of crude 
vision in these creatures, is somewhat aside from the 
evidence, that doubtful or imperfect ability to see is not 
reflected in the facility with which they find their way 
out of the water to a desirable breeding spot. Well, 
then, here is my proof. The thing that first struc!' 
me that they were practically insensible to surrounding 
objects through the aid of vision was their utter in- 
capacity to avoid any obstacle happening to be in their 
way. In traveling over the surface of the bottom, 
however well lighted, they would collide headlong with 
stones and other prominent barriers in their path, and 
only by repeated trial and effort did they chance to cir- 
cumvent them and proceed in the general direction they 
were bent. It was the same with the mating individuals 
who came out of the water to spawn. I would stand 
directly in the line of their approach, but they would 
continue straight ahead, heedless of my existence, until 
brought to a stop by coming into contact with my boots. 



232 Dwellers of the Sea and Shore 

Moreover, while in the water, these animals never 
seemed aware of my presence until I actually touched 
them; whereupon the merest contactual disturbance 
was enough often to cause them to strike out for the 
deeper regions. This is what gave me a hint. 

I am going to put the cart in front of the horse, 
somewhat, by saying at once that Limulus, after the 
manner of creatures totally blind, makes its way by the 
sense of feeling, and it determines its direction, or gen- 
eral course, by the slope of the substratum. Let us 
try an experiment. Taking for the purpose a full- 
grown individual, we cover both its simple and com- 
pound eyes with asphaltum or some other dense pig- 
ment — an operation by no means distressing to the 
animal since in this case the cornea is as hard and 
feelingless as the carapace. Then placing the creature 
on the hard-packed sand near the water's edge, we 
watch its movements. Does it grope about, uncer- 
tainly, hesitatingly? Not at all. No matter in which 
direction it is set — with its head pointed either toward 
the sea or the land — it crawls unerringly toward the 
water. In other words, it follows the declivity of the 
sand, however slight this may be. But in this matter 
it can be deceived. If it be placed on the side of a 
ridge that slopes away from water, it will amble to a 
lower level, and not finding water it will force itself 
into the sand. By removing the pigment and repeating 
the process the result is the same. We may be sure 
that it is by the same principle that the breeding ani- 
mals are guided in their course up the beach when the 
water is low. And these journeys are not infrequently 
over surfaces sometimes comparatively slight in pitch. 



A "Living Fossil" 233 

For, by covering the eyes of a pair which are obviously 
about to leave the water, and turning them in the oppo- 
site direction, we find that they soon arrive at their 
destination regardless. 

That Limulus can detect light from darkness, there 
is, of course, no question. This is borne out by the very 
structure of both the compound and the simple eyes. 
But this is not seeing, in the sense that humans or the 
higher animals see. Externally, the compound eyes ap- 
pear to be divided into a number of circular facets, each 
barely touching its neighbor. Every facet is the cover- 
ing of a unit that is a complete eye in itself. In sub- 
stance, the individual unit is composed of the cornea, 
which is simply the crust specialized by becoming trans- 
parent, and the cone, or crystalline lens. It is this lens 
that In the eyes of most other animals forms the optical 
image; but in Limulus it seems to be a very imperfect 
affair. A continuation of the crust invests the cone 
which is perforated at the apex, and this in turn is ter- 
minated by a rod surrounded with nerve fibrils arising 
from the optic nerve. The inside of the cone is lined 
with an opaque pigment that prevents the rays of light 
from passing from one facet eye to another. The 
ocelli, or simple eyes, are still simpler in their construc- 
tion. They are in truth quite primitive. Their pig- 
mentation is irregular and they lack the nervous 
organization of the compound unit. One peculiarity 
of compound eyes in general should be mentioned here. 
It is well known that many insects and crustaceans have 
remarkable vision. Now, in all those cases in which 
good vision inheres, the facets of the eyes are arranged 
in a geometrical pattern as if from compression; viz., 



234 Dwellers of the Sea and Shore 

hexagonal, rectangular. On the other hand, where the 
facets are mere circular units unmethodically arranged, 
such as is found in the so-called u silver fish" and certain 
isopods, quickness of perception is lacking. The eyes 
of the horseshoe crab are of this type. Just what is 
the connection between a compound eye composed of 
a loose aggregation of units and its want of acuteness 
is hard to determine. Nor is it easy to say why Lim- 
ulus, which seems to be neither crustacean nor insect, 
yet possessing two pairs of eyes, one pair actually con- 
sisting of nearly two thousand smaller eyes, does not 
make better use of its endowment. Nevertheless, if 
one were to hazard the guess that here we see the 
compound eye of higher animals in evolution, he would 
probably be not far from the truth. For it is a sig- 
nificant fact that all creatures distinguished by what 
appears to be this primitive form of compound eye are 
creatures of a very ancient type; they differ but little 
to-day from their fossils which were formed millions 
of years ago. Down through the ages which saw count- 
less other forms appear and then vanish away, they and 
our Limulus have survived practically unaltered in 
form. 

The eggs spawned by a large female horseshoe crab 
number upward of ten thousand, enough almost to fill 
a half-pint jar. They are spherical bodies measuring 
about one twelfth of an inch in diameter. In color they 
are green. Under the microscope will be seen in each 
egg a large, smooth granular yolk nearly filling the 
tough, transparent membrane that acts as a shell. The 
rate of development of the embryo depends on tem- 
perature and, to some extent, light. In a cool place and 



A "Living Fossil" 235 

dark situation the hatching can be retarded for a year; 
but under average normal conditions, such as will be 
assumed to be the case in this account, the period of 
incubation is far less. 

About a week or so after the eggs are laid there 
appears on the surface of the yolk an oval constriction 
bearing six pairs of appendages in a row. They are the 
merest sort of prominences and represent what will be 
in the adult the legs. At this time, too, a faint indi- 
cation of what is to be the abdomen can be seen toward 
one end of the oval. The ovoid region now continues 
to grow while the yolk gets visibly smaller until the next 
stage of the embryo is reached, wherein we find not 
only an enlarged abdomen with four transverse sutures 
denoting the formation of segments, but a distinct head 
region on the back of which are strongly indicated five 
segments. This occurs about three weeks after spawn- 
ing and by this time the cephalic legs have increased in 
size, are jointed, and are folded upon themselves, and 
rudimentary gill feet have appeared on the abdomen. 
It is now, for the first time, that the embryo shows 
movement. The membranous shell has increased in 
size, leaving ample space within which little Limulus 
continually revolves. 

A couple of days later occurs the animal's first molt. 
Increasing growth has caused it to outlive its old skin, 
and cast it off within the egg, just as it will continue to 
do in its larval and later stages. The body is here quite 
plump, or globular, and is provided with two pairs of 
eyes, simple and compound. From now on the body 
gradually flattens. And when, a little later, or about 
a month and a half after spawning, the egg is due to 



236 



Dwellers of the Sea and Shore 



hatch, a striking revelation greets us in the appearance 
of the embryo. It has become distinctly trilobate in 
character. As in the trilobite, a highly arched ridge 
runs lengthwise over the middle region of the body, the 
sutures between the segments of the hind body are 
somewhat bent, and the outer edge, or lateral plate, 
of each segment is strongly convex. 



y<Cr^ ;'■>■■• . • •*»■: .••;,."<. -«.:&ss*bv 

>fv/f*»\ •>•:•• ■ ■ •"••♦ ••••..*.• "f&lisV 

.-.-'V? ; . * •.-. . :•• ■ . . . •/■ .": .: -'J-- ;V*- -" 

$£*../-. /. = .■..;.;.... ;•'.' • • ■ -••■>/•, • - 7V r .v r'''"i;-- V^, ; 



. 



■^°&. 



'M&MMM 



TRILOBITELIKE LARVA OF THE HORSESHOE CRAB. 

Finally the membrane ruptures and liberates the 
larva. The larva differs from the embryo in that the 
abdomen is broader and flatter, and that the sutures 
between the lateral plates have disappeared, leaving 
segmented only a keellike middle ridge. It is now a 
little more than a tenth of an inch in length and a trifle 
less in breadth. Immediately it shows great activity 
by vigorously striking out into the water and swimming 
away. For about three weeks it lives a more or less 
nomadic life, wandering widely in this period, when at 
the end it molts and settles to the floor for good. With 



A <( Living Fossil" 



237 



this molt it loses entirely its segmented appearance and 
now more nearly resembles the adult. A short spine- 
like tail adorns the abdomen; the abdomen is thin, and 
this region, like the cephalothorax, is hollowed out 
underneath, the whole forming an ample shield for the 
legs and gill feet. 




HORSESHOE CRAB MOLTING. 



When Limulus is a year old it attains to an inch in 
length; by then it has molted several times. But not 
before it is in its fourth year does it reach sexual ma- 
turity. In that event the male acquires the strong front 
claws that distinguish his sex. 

Thus, in following the development of Limulus, we 
see revealed with remarkable distinctness its ancient 
origin. It is not always so easy, however, to trace the 



238 Dwellers of the Sea and Shore 

antecedents of our higher animals. The threads that 
unite them with the past are often tangled and some- 
times broken. But all such as we have been able to 
guide ourselves by lead to the inevitable conclusion 
that, like the horseshoe crab, every other living many- 
celled creature had its beginning in a form which has 
now long since perished forever. And it is to the story 
of the unraveling of those strands and the uniting of 
the broken ends that natural science owes some of its 
most thrilling, most romantic, and most luminous pages. 






Chapter XIV 
MORE FRIENDS IN ARMOR 

How "fiddler crab" came to be the popular name of 
the crustaceans which forms the subject of this chapter 
is not easy to determine. On consulting the books, I 
find reasons as various as they are numerous. The 
most likely explanation, perhaps, lies in the allusion to 
the single enormous claw carried by the male. It is said 
that the back-and-forth movement of that claw re- 
sembles the act of fiddling. Well, this may appear so 
to some people; but it seems to me a far-fetched peg 
upon which to hang a name. The Japanese have a 
more apt and much prettier term. They call it siho 
manek'iy "beckoning for the return of the tide." 

Whether right or wrong, its common name is at least 
definite and durable. It has never been known by any 
other English name; and when one speaks of a fiddler 
crab there is no misunderstanding as to what sort of 
creature is meant. The nomenclature of science has 
not been so happy. Since the fiddler crab has come 
under the cognizance of the learned systematists, it has 
paraded under at least four different formidable Latin 
terms, and all of them of an even more doubtful sig- 
nificance than that which is born by its popular one. 
An instance in point is Gelasimns pugilator. This name, 

239 



240 Dwellers of the Sea and Shore 

meaning u a laughable fighter," is given to a crab of 
my region. But in my contact with it in the salt 
marshes, where it honeycombs the ground with its bur- 
rows, and where it is to be observed not in hundreds, 
not in thousands, but in millions, I have not yet seen the 
least display of pugnacity toward its fellows or toward 
humans. Uca m'inax, u the threatener," the present 
name of the species whose habits I propose to describe, 
is hardly less inept. It is true that none among our 
armor-bearing creatures wears so threatening a pan- 
oply, but the male, in his possession of a clumsy and 
apparently quite useless claw, is far from a threatening 
creature. This prodigious appendage is entirely want- 
ing in the female, whose chelipeds are small and of 
equal size. Just why the male, who generally carries 
it at rest across the broad front of his carapace, is thus 
distinguished does not seem clear; for at no time does 
it appear to be anything but an encumbrance. 

Our fiddler crab (Uca minax) is not a large crab, 
as crabs go, being not much more than an inch and a 
quarter over the breadth of its carapace. It likes to 
live in a region of brackish water, on the open, sandy 
reaches at the very upper limits of the tide near where 
the marsh grass starts to grow. Here it depends for 
food on the minute algal deposits left twice daily at its 
door by the tides. Vegetable matter is not its whole 
diet, however; it will greedily attack any bits of carrion 
which chance to come within its range. It prefers its 
victuals fresh. Unlike the true scavengers of the shore, 
its meat must have no suspicion of being stale. But 
opportunities of this kind are rare, and it is perforce 
obliged to subsist for the most part on what plants will 



More Friends in Armor 



241 



suit its taste. Whenever it leaves its burrow — and it 
seldom wanders from it more than a few feet — it can 
be seen picking about in the sand and silt, carrying the 
all but invisible motes of matter to its mouth. Some of 
this matter is sand; mixed with it are the food particles 
that it seeks. For this burrowing animal, in learning 




FIDDLER CRABS. THE MALE, WHO IS READILY DISTINGUISHED BY HIS LARGE CLAW, 
IS TOWARD THE LEFT OF THE PICTURE SITTING IN THE OVENLIKE ENTRANCE 
TO HIS BURROW. THE OTHER INDIVIDUAL IS THE FEMALE. PELLETS OF 

EXCAVATED SAND CAN BE SEEN IN THE FOREGROUND. 



to live on land has learned the same lessons as the 
earthworm: in the absence of more available products, 
it eats the soil to live. 

The burrow of our fiddler crab can readily be dis- 
tinguished from those of other species by the archway, 
or ovenlike mound, over the mouth. Many of these 
ovens will be found within the space of a single yard. 



242 Dwellers of the Sea and Shore 

After the frosts have gone they begin to make their 
appearance, and by the time the scorching heat of sum- 
mer has set in they become so numerous along the edge 
of the marsh that they are countless. The diameter of 
the shaft varies; those of the young are less than the 
thickness of a match, while the adults sometimes make 
holes into which a hen's egg could be dropped. These 
latter are sunk to the greatest depth; they rarely reach 
more than a foot. At the bottom a horizontal tunnel 
less than a finger's length is often, though not invari- 
ably, projected. 

Excepting during the breeding season, only one crab 
occupies a burrow. When the tide is out, this individual 
can be seen sitting for long periods in the arched door- 
way, without movement or any sign of life other than 
an occasional twitch of its eyestalks. But it is fully 
alive to what is going on around it; if the observer so 
much as raises an arm, the creature disappears instantly 
down the shaft. Then, if one waits for a while, one 
will see it cautiously and slowly reappear to take its 
place at the entrance. 

Since the fiddler crab makes its burrow at or very 
close to the high-water mark, its home is inundated for 
only a short while at each flood. This allows it ample 
opportunity to wander around. Yet it never goes far 
afield, seeming to prefer its doorstep to the allurements 
of travel. It is certainly not due to any inability to get 
over the ground that it chooses to lead a sedentary life. 
It is, in fact, a very nimble runner. When surprised at 
its business of searching for food some few feet away 
from its hole, it will rush to its retreat with remark- 
able speed. And to intercept it, one must be more than 



More Friends in Armor 243 

ordinarily agile, for so alert is the animal that, on find- 
ing its way blocked, it will scamper down the nearest 
of the neighboring burrows. Still, in spite of its 
activity and the protection afforded by its place of 
hiding, it is the prey of numerous enemies. These are 
chiefly birds. The blue heron knows its habits well. 
This long-billed and long-legged creature stands 
motionless over the burrow waiting for the crab to 
come out, and no sooner does the latter make its ap- 
pearance than it is silently and swiftly snatched from 
the ground and devoured. 

Although the fiddler crab seems not yet to have 
learned how to escape its enemies of the land, it has an 
inheritance that stands it in good stead in avoiding its 
foes of the sea. But dangers from that direction are 
few. It is extremely infrequent that the crab finds itself 
unexposed on the bottom. When it takes to the water 
at all it is in some shallow pool or equally safe and shel- 
tered place right at its door. When the tide rises over 
its burrow it rarely ventures out, but remains secluded 
within until after the flood subsides. The peculiar 
marbled pattern on its back, together with the trans- 
lucent appearance of the legs, make it barely distin- 
guishable in the water from the sand on which it rests. 
It has some facility in changing its hues from lighter to 
darker tones, according to its situation, and almost 
every color of the rainbow is represented on some part 
of its body: from the bright red of the joints on the 
legs to the soft -blues and greens and buffs that beau- 
tify its back, the range of tints is so wide and their 
nuances are so exquisitely delicate as to make it easily 
among all brachyurans the most charming to the eye. 



244 Dwellers of the Sea and Shore 

This is to say, while it is in the water. Out of that 
medium these features lose their delightful character- 
istics. And, furthermore, it is on the dry land that the 
creature spends the greater part of its existence; so, in 
a sense, the beauty that is the fiddler crab's is attained 
under unusual, if not unnatural, conditions. 

Now it must by no means be assumed that the crab 
is a terrestrial animal living in proximity to the sea, 
that it could live, if need be, on the dry land. The 
truth is quite the reverse. It can be kept continuously 
in the water without harm. Nor will it long survive its 
absence. In a way of speaking, water is to this creature 
the very breath of life; but it gets all that is necessary 
for its needs during the short time it is submerged by 
the tides. Except for this temporary, but very vital, 
contact, it has slight acquaintance w T ith an aquatic life. 

How does the fiddler crab breathe? How is it that 
a creature possessing only gills, which we know are 
strictly water-breathing organs, can with equal facility 
breathe in the free air? Strictly speaking, it does not 
breathe the air direct. Its gills lie in two large cavities 
on the back just under the carapace. These cavities, or 
chambers, are considerably larger than the gills them- 
selves and are in reality receptacles for the storage, or 
retention, of water. When the crab is submerged, an 
opening to the front of the chamber allows a free cir- 
culation of water to enter and bathe the gills, which 
absorb the necessary oxygen to sustain the animal. Out 
of the water, however, the opening closes, and the re- 
tained water absorbs oxygen from the atmosphere, 
which in turn is transmitted to the gills. 

When the rising tide reaches the level of the 



More Friends in Armor 245 

burrows, it finds every crab safely underground, 
completely out of sight. More : it finds the ovens 
demolished and the entrance to the shafts plugged up 
with sand. In truth, our fellow knows well the time of 
high water, it seems, for it anticipates its arrival by 
having sealed its shaft within a half hour of the moment 
it is submerged. For the purpose of stopping up the 
hole, the crab uses the material of the archway and 
scrapes up what is necessary from around the door. 
This it gathers up in great pellets and packs solidly at 
the mouth, forming a plug an inch or more deep. The 
advantage in thus stopping up the shaft is obvious. It 
saves the inmate an enormous amount of labor. Were 
this not done and the holes left open, the action of the 
water would fill them with silt or cause the sides to 
crumble in, and by thus burying the occupant cause it 
no small inconvenience and hardship by obliging it to 
construct its entire burrow anew after every inundation. 
Even as it is, the crab is put to considerable effort 
when the tide lowers. For the seepage of the water 
loosens the wall which in the first place is none too well 
consolidated, and some sand invariably falls away from 
the sides. To reopen the passage, it first pushes up the 
sand that plugs the entrance. This loosened material 
forms a mound at the top, and the crab works its way 
out at the base, which results in giving to the little 
tumulus its ovenlike character. After which the animal 
returns to the burrow and scoops up a load of sand, 
compacting it into a pellet of about the size of a cherry, 
and proceeds to carry it out and deposit it a few inches 
from the mouth. This performance is repeated several 
times until the tunnel is thoroughly cleared, the crab in 



246 Dwellers of the Sea and Shore 

its sidewise progress pulling the pellet along by holding 
it in the hollow formed by the curvature of its rear- 
ward legs. Every burrow has a number of these char- 
acteristic pellets in its vicinity. At best, the burrow of 
the fiddler crab is a temporary affair; the animal alter- 
nately building and abandoning many homes during the 
course of the summer. 

I have alluded to the presence of more than one 
individual in a shaft. With the arrival of summer 
comes the call of love. The amorous pairs, whose 
embraces last the greater part of a day, seek the seclu- 
sion of the horizontal tunnel at the bottom for their 
tryst. Throughout the whole of June, I find, on prying 
into various retreats, many couples so engaged. At 
this time, too, the male seems heightened in color, the 
red patches on his ponderous cheliped becoming de- 
cidedly garish. He affects his best raiment for the wed- 
ding. The marital life is not for long, how T ever; no 
sooner have they relinquished their embraces than they 
separate for good. 

During this month many females can be seen bearing 
a large, dark-red spongy mass on the abdomen. It 
would not be hard to guess, even without the lens, that 
this sponge is a batch of eggs. But the jars of my lab- 
oratory will give us more information about them than 
could possibly be obtained at the beach. So let us col- 
lect a few of these fertile females: the thing is easy, a 
thrust of a spade will quickly unearth any who have 
disappeared in their burrow T s. Then transferring our 
pretty creatures to a pail of salt water, we take them 
home. One point should be noted here which may be 
of value later in our observations : contrary to the usual 



More Friends in Armor 



247 



habits of the fiddler crab, some of the sponge-bearing 
females spend quite as much of their time in the water 
of the neighboring pools as under the archway of their 



ovens. 



With our captives installed in two-quart jars, half 
filled with sea water and a layer of clean sand on the 
bottom, we await developments. Each tank holds one 




FEMALE FIDDLER CRAB. THE DARK MASS ON HER ABDOMEN IS A BROOD OF EGGS 
AND IS KNOWN AS THE "SPONGE." 



female, and her jar is kept nice and fresh by the 
addition of a frond of sea lettuce. A cool, well-lighted 
place at a north window insures results more nearly 
approaching those under natural conditions. In the 
meantime a closer inspection of the animals may be 
profitable. 

It was pointed out in an earlier chapter that the true 
crabs, or brachyurans, in contradistinction to the lob- 



248 Dwellers of the Sea and Shore 

sterlike crustaceans, or macrurans, have a relatively 
small hind body. In the fiddler crab, which is a typical 
example of the Brachyura, the cephalothorax, or the 
fore body, is flattened and broader than it is long. The 
small, flat, segmented abdomen is folded under the fore 
body and fits in a depression, making it appear to ordi- 
nary eyes as if the creature's entire body were one rigid 
piece without a division of hind or fore body. As a 
matter of fact, the abdomen, though invisible from 
above and inconspicuous when the animal is viewed 
from underneath, is a very important part of the crab's 
anatomy. In the male it carries the external parts of 
the sexual organs, while in the female it has on the 
under, or what may appropriately be termed the inner, 
side four pairs of prominent hairlike appendages called 
the swimmerets. It is to the swimmerets that the ex- 
truded eggs are attached, forming the spongy mass. It 
may be added that the hind body of the male is com- 
paratively narrow, whereas that of the female is very 
broad; a feature that readily enables the determination 
of an individual's sex, which is not always obvious in 
the case of the males, who ofttimes have lost their dis- 
tinguishing claw. 

The eggs in reality are divided into eight clumps cor- 
responding to the four pairs of swimmerets, but they 
are so closely packed that they seem to form one 
large group. The mass is flattish and seems to be 
wedged solidly between the thoracic region and the 
abdomen; its bulk is about that of a navy bean's. But 
so small are the individual units that more than seventy- 
five thousand are contained within this space. Herein 
is the secret of the fiddler crab's persistence, who, de- 



More Friends in Armor 249 

spite its manifold enemies, succeeds in maintaining its 
enormous numbers. The microscope, that third eye of 
the investigator, tells us that each egg is attached to the 
fine hairs on the inner branches of the swimmerets by 
a stalk. The stalk is a continuation of a membrane 
investing the egg and the hair to which it is fastened. 
Numerous eggs are fixed to the same hair, and the 
whole is not unlike a long stem supporting a cluster of 
berries by short pedicels. The eggs are fertilized 
while in the body of the female. When first laid they 
are of a deep orange color, but soon turn dark 
red; and as hatching time approaches, they become 
a deep brown, due to the black eyes of the growing 
embryo. 

Within a fortnight after the jars of my laboratory 
are established, my anticipations are realized. Every 
one of the females has hatched her brood. My atten- 
tion is first attracted to this event by a cloudlike haze 
on that side of the tanks which is nearest to the light. 
This observation may give us some idea of the length 
of time the mother has been burdened with the eggs. 

A dipping tube inserted into the hazy swarm takes 
up hundreds of the young larvae, and a drop of water 
released on a microscope slide brings several within 
easy compass for observation. Under a low-power lens 
the little creatures can be seen actively cavorting across 
the field, their movements closely resembling the wrig- 
gling progress of mosquito larvae. They are trans- 
lucent throughout their bodies, except for the large, 
prominent compound eyes, which are black. There is 
no similarity to their parents. The head and front part 
of the body are covered with a helmet-shaped carapace 



250 Dwellers of the Sea and Shore 

having a long curved spine standing out from the 
middle of the back, and another straighter one pro- 
jecting, like a beak, in front. The hind body is much 
smaller. It is narrow, segmented, and ends in a forked 
tail, or telson. It is also very flexible, and can be bent 
under the fore body or straightened out behind. There 
are several pairs of delicate appendages on the fore 
body, but the most conspicuous are the two pairs of 
swimming legs ending in featherlike branches. Actu- 
ally, the two-branched swimming legs are appendages 
belonging properly to the mouth, the real legs of the 
crab being not yet in evidence, and, although the seg- 
ments of the abdomen are distinct, they are devoid of 
swimmerets. 

This description of the first larval stage of the fiddler 
crab applies with almost equal correctness to the newly 
hatched larvae of every member of the marine Brachy- 
ura, or crabs. It is a typical form and for that reason 
it is known as a zoea f a name which it received when it 
was thought to be a separate and distinct species of 
crustacean. Some land crabs differ slightly in their 
earliest larval appearance. That the zoea were once 
thought to be an independent species was due to the 
fact that the development of the fresh-water crayfish 
was known long before that of other crustaceans. In 
that creature the young when hatched from the egg 
are practically like the adult, and it was therefore 
assumed that all crustaceans were developed alike. 
Indeed, the larval stages of marine forms were known, 
but their actual identity was not suspected. And even 
after their true nature was discovered, after their 
metamorphoses had been studied and described, many 



More Friends in Armor 



251 



eminent naturalists "refused to believe in the possi- 
bility of their occurrence." 

The next and last larval stage, which is also peculiar 
to the crabs, takes place in our animal about a month 
later. In this stage the larva, known as a megalopa, 
spends most of its time swimming about at the surface 




x 



ZOEA OF THE FIDDLER CRAB. CgREATLV ENLARGED.,) 

of the water. From the evidence of its behavior in the 
tanks, it is plain that during this period of its life it 
roams far and wide. Then it is that the necessary dis- 
persal takes place to prevent overcrowding in one 
locality. It has shed its zoeal skin, and now appears 
with all its appendages. The spine on its back is miss- 
ing, the one in front much shortened, and its eyes are 
stalked and movable; except that the hind body is 



252 Dwellers of the Sea and Shore 

extended straight out in the rear instead of being bent 
under the fore body, it does not differ greatly from a 
little crab. It is by means of the swimmerets on its 
abdomen that it propels itself, and in view of the nata- 
tory life led by the larva it is easy to understand the 
predilection of the burdened female for the water. 
Were her tender babes to burst their swaddling clothes 
while she sat on the scorching sands, their lives would 
be in grave peril. But just as frequently, she remains 
in the humid retreat of her burrow when the hatching 
is due to occur; the little ones later finding their way 
out in the waters of the tide. 

A week or so later the megalopa molts; this molt 
bringing it directly into existence as a young crab. The 
little creature, who is not much larger than the head 
of a pin, immediately settles down in some likely area 
near the high-water mark and starts to burrow. 

From now on it will live like its elders, picking what 
it can find to eat from the sand and silt. Without 
going into tedious details, I can say that from what 
deductions are possible from my tanks, and from 
further observations at the shore, the probable develop- 
ments in the future life of the fiddler crab are as 
follows : Full growth is not attained until it is nearly 
a year and a half old; that is, in the fall of the following 
year. This growth is signalized by successive molts 
which occur at least twelve times. The castings of the 
crust take place more frequently in the early than in 
the late part of the animal's growing life. After it 
reaches maturity, the moltings no longer occur. There 
is evidence that pairing happens during, or shortly sub- 
sequent to, the molting period of the female. Other 



More Friends in Armor 253 

evidence suggests that the female may have more than 
one brood after a single meeting with the male, and 
that she dies soon after her last bearing. The crab's 
term of life is three years. 

To say that the fiddler crab grows when it molts 
would be to express the reverse of what is true. The 
fact is, the creature molts because it grows. The soft 
tissues increase in content, but the hard, rigid armor is 
incapable of expansion; therefore this must be cast oft. 
In the process of shedding, a crack appears in the crust 
along a line at the rear edge of the carapace. The 
crab literally backs out through the opening thus 
started, and as it does so it forces the carapace up, 
extending the fissure on both sides to the front, making 
its egress easier. This operation is performed by a 
series of peculiar rhythmic tremors, and it takes about 
twenty minutes to accomplish. When the animal is 
finally divested of its shell, it appears soft and wrinkled 
on the surface, and, although it can walk, it is truly a 
quite helpless individual. Were it not for the fact that 
this critical period is passed in the saturated precincts 
of its cell, it would, besides running the chance of suc- 
cumbing to the first evil passer-by, be subjected to con- 
siderable discomfort in the rays of the sizzling sun. 
But it soon fills out and the skin begins to harden. A 
day or so hence finds it once more sitting in the door- 
way or picking at the sand. 

Molting has its advantages in other ways. If a 
young crab has lost an appendage a new one appears 
at the time of some successive casting of its armor. It 
is a common phenomenon among crustaceans to throw 
off a leg or claw when the individual is seized by one 



254 Dwellers of the Sea and Shore 

of those members. This is an automatic process, which 
is to say, it is not due to external force as such. Tech- 
nically it is known as autotomy, meaning "self-cutting." 
The separation of the appendage usually occurs at a 
point on one of the segments close to the body, and 
serious as it may seem at first sight there is little danger 
to the animal; the tissues of the stump constrict, thus 
preventing excessive bleeding, and the loss is often only 
temporary. If it happens just after the crab has shed 
its skin, another takes its place at the following molt; 
if the loss is sustained a short time before the shedding, 
the second succeeding molt will complete the regen- 
eration. 

From this it would appear that the full-grown ani- 
mal, having completed all the molts necessary to attain 
its growth, is unable to regenerate lost appendages. So 
far as my observation extends, this is actually the case. 
Yet an old crab will as readily cast off a claw as will a 
young one. It is plain, nevertheless, that in any event 
this capacity is to its decided benefit; for, truth to say, 
it is better to lose a limb than to lose a life. 



PART THREE 
THE OPEN SEA 



Chapter XV 
BEYOND THE HORIZON 

It is a remarkable fact that there are few living 
marine animals which are more constantly brought to 
notice than those ranging the open sea, and yet there 
are not many whose habits and life histories are more 
completely unknown. The very nature of their haunts, 
of course, makes it more difficult to observe them than 
would be the case if they w r ere associated with the 
shore. What information has been obtained regarding 
their food habits has been derived not so much by actual 
observation as by the more indirect, but certain, method 
of examining the stomach contents of captured speci- 
mens. However, except in relation to a few forms, 
positive information of the behavior and development 
of the vast majority that roam the deep is extremely 
scant. 

Examination of the ingested food of oceanic ani- 
mals, by the way, has revealed the existence of many 
creatures hitherto unknown. Whales and large fishes 
are particularly valuable in this respect; in their pred- 
atory excursions they pick up more strange species than 
do the nets of the naturalists. 

Probably none of the sea rovers are as often con- 
nected in the popular mind with the open sea as are the 

257 



258 Dwellers of the Sea and Shore 

whales and sharks. Much misconception, however, 
exists regarding these creatures. Each comprises a 
numerous group. Not all whales are the large, pic- 
turesque animals romantically featured in stories; not 
all sharks are dangerous. 

The whales, in modern classification, belong to 
that order of mammals distinguished by the Greek 
name Cetacea ) a word meaning u sea monster" and 
once indiscriminately applied by the ancient mariner 
of the Mediterranean to all large and strange oceanic 
creatures. Now, as the cetaceans are mammals, 
and since we know that mammals are warm-blooded, 
lung-breathing animals which suckle their young, it 
will be seen that the whales are very far from being 
fishes. In the whales, however, the hairy coat that is 
usually characteristic of mammals has almost entirely 
disappeared, its property of protecting the animal from 
the cold having in this instance been assumed by the 
thick layer of peculiar fat, called blubber, under the 
smooth skin. The only reminder of a former hairy 
coat is to be found in some very young whales, wherein 
the presence of a few bristles about the lips indicate a 
hirsute ancestor. Indeed, one of the striking charac- 
teristics of these creatures is the total dissimilarity of 
their outward appearance to other mammals. Even in- 
ternally many modifications are to be found. The hind 
legs have disappeared, but they have left within the 
body remnants of the pelvis and thigh bones; in some 
instances the leg bones themselves still remain. The 
peculiarity of the fore limbs is quite marked in that the 
arm bone is very short and broad; whereas in other 
mammals all agree in having the same number of joints 



Beyond the Horizon 259 

in the fingers and toes, in the whales these numbers 
invariably are exceeded. In some instances the fingers 
have more than twenty joints, a feature greatly re- 
sembling the many-jointed flipper of the extinct Ich- 
thyosaurus and allied prehistoric marine lizards. The 
flippers, usually small though sometimes of considerable 
length, are not used to propel the animal in swimming, 
seeming to be more for the purpose of maintaining its 
equilibrium or keeping it on an even keel. It swims by 
the sculling action of the flukes of its great tail which 
is not placed vertically as in fishes, but horizontally. 
This position is better adapted to the requirements of 
the animal which must needs often seek the surface for 
air to breathe. 

Cetaceans, although having many features in com- 
mon by which they are easily identified from other 
mammals, nevertheless differ considerably from one 
another. As I have already observed, one of these 
differences is in respect to size. Some, the smaller dol- 
phins, are less than a yard long; the other extreme is 
found in the blue whale, or rorqual, which is said to 
be nearly ninety feet in length. But there is a more 
fundamental difference than that of mere size; and it 
is one which has caused them to be divided into the two 
great groups that naturalists now refer them. These 
are the w T halebone whales, or the Mystacoceti, and the 
toothed whales, or Odontoceti. 

Even the members of each of these groups exhibit 
enough differences to make further divisions possible. 
The whalebone whales are split into two families which 
in turn are subdivided into genera and species. In one 
family are included the so-called u right whales," and 



260 Dwellers of the Sea and Shore 

in the other are the rorquals and the humpbacked 
whales. But the difference between the families is one 
of degree rather than of kind. In the right whales, 
known technically as the Balanida, the whalebone is 
very long; in the other whalebone whales, the Balanop- 
terida, the whalebone is comparatively short. Further- 
more, the right whales have no dorsal fin, while the 
rorquals invariably are possessed of this appendage, 
though in some specimens it is rather small. Another 
means of identification for those who chance to meet 




GREENLAND WHALE. 



with them at sea is by their manner of disappearing 
under the surface. The right whales dive with the 
great head almost straight down into the water, throw- 
ing upward the flukes of the tail, while the rorquals, on 
the other hand, sink out of sight gradually, much in the 
way that a submarine boat disappears from view. 

The most famous of the right whales is the Green- 
land, or Arctic, whale. This is the true polar species, 
seldom or never being found far from the Arctic ice. 
It was at one time the object of a great European 
fishery. Holland, England, and France were chiefly 
engaged, but a large Dutch settlement in Spitzbergen 
employed no less than 260 ships and 14,000 men in 



Beyond the Horizon 261 

the profitable business of hunting and killing these crea- 
tures. That was in the seventeenth century when the 
whale fishery was at its height; to-day the Greenland 
whale is practically extinct. It has entirely disappeared 
from the region of Spitzbergen and the waters of 
Greenland where it once existed in such plenty, and 
now only a few small wandering herds may occasionally 
be encountered in the neighborhood of Bering Sea. 

This species (Balana mysketus) is the largest of the 
right whales, reaching a length of about fifty feet. 
Over the back and sides it is a deep blue black, under- 
neath it is gray, while the neck and throat are white. 
The enormous head fully exceeds a third of the crea- 
ture's total length. Actually, the cavity of the mouth 
is larger than that of the body. Yet as gigantic as are 
the jaws of this animal, the gullet is comparatively 
diminutive, being less than two inches in diameter, and 
it subsists on nothing but very small organisms. Its 
food consists principally of minute crustaceans and free- 
swimming mollusks (pteropods) , which swarm in im- 
mense shoals in the colder seas. In the capture of its 
food, the value of its inordinately large mouth becomes 
at once apparent. It is thereby enabled to engulf at 
one time a sufficient quantity of water containing the 
organisms. When the creature closes its jaws, these 
are held in by the straining action of the whalebone 
which allows only the water to pass through and out at 
the sides of the mouth. The whalebone blades in the 
animal are not exactly as they appear in the article with 
which we are all more or less familiar; they are here 
frayed out at one — the inner — edge and at the ends 
into long soft and silky but extremely tough hairs. 



262 Dwellers of the Sea and Shore 

They hang in two rows from the upper jaw, a row on 
each side of the mouth connected by a group of shorter 
blades in front where the jaw arches down, but those in 
the middle where the arch is highest are very long. 
Sometimes they have a length of twelve feet. There 
are nearly four hundred on each side, and the whole 
quantity in the mouth of a large specimen often weighs 
close to two tons. 

Many species of right whales have been described, 
but naturalists are not quite agreed as to their number 
or distinctive characteristics. For instance the Bis- 
cayan whale (B. biscayensis) is supposed by some to be 
identical with the black whale (5. australts) . The 
former differs from the Greenland whale in having a 
smaller head and a correspondingly shorter length of 
whalebone. This species frequents the colder waters 
of the northern hemisphere, but its range is very wide, 
having been found as far south as the Azores and Ber- 
muda and even in the Mediterranean Sea. It was once 
thought to be extinct; it has, however, been seen re- 
cently in considerable numbers in the North Atlantic. 
The black whale inhabits the southern hemisphere in 
the neighborhood of Australia, New Zealand, and the 
Cape of Good Hope, in the latter region of which I 
have been so fortunate as to sail through several small 
herds of them. That was more than twenty years ago, 
and it would be nearly correct, perhaps, to say that the 
black whale no longer inhabits the southern seas, for 
owing to the wanton slaughter of the females as they 
visited the coastal bays and inlets to breed, their exter- 
mination is almost complete. Another right whale is 
one (B. japonica) which ranges the northern half of 



Beyond the Horizon 



263 



the Pacific Ocean from the Siberian Sea of Okhotsk to 
Oregon. The Japanese from very early times have 
hunted these creatures; however, in late years the 
American and Russian whalers have made considerable 
inroads on their numbers. Here, too, the specific dif- 
ference from the Biscayan whale and the black whale 
does not seem to be well marked. The condition in 
which they are brought to shore does not make it easy 
for thorough comparisons. It is probable, though, that 
if any differences do exist, they are very slight. 




RORQUAL. 



The rorquals and humpbacked whales resemble the 
right whales in their habits, and except for the presence 
of a dorsal fin and having much smaller heads, they 
correspond with the other in general structure. But a 
peculiarity exists in the appearance of these animals 
which is unique: the skin under the throat is lined in a 
lengthwise direction with long parallel ridges and 
grooves, or plications. As I have said, some of the 
rorquals have been alleged to measure nearly one hun- 
dred feet; they are larger than the right whales, and 
indeed are the largest of all known animals, living or 
extinct. Of all the whalebone whales they are the 
most abundant and widely distributed, being found in 
almost every sea. They live on minute organisms, 



264 Dwellers of the Sea and Shore 

but some will feed on fishes, for they have often been 
observed feasting among herring shoals and schools 
of an Arctic species (Osmerus arcticus) . 

When we turn to the toothed whales, we find not 
merely a difference in the dental equipment but there is 
a marked change in the food habits and generally in 
geographical distribution as well. This group, the 
Odontoceti, is a numerous one, the most noteworthy of 
which are the sperm whales, dolphins, and porpoises. 
The largest of these is the sperm whale (Physeter 
macrocephalus), known sometimes as the cachalot, 




SPERM WHALE. 



which attains to a length of over sixty feet. Its char- 
acteristic gigantic head, with the straight, blunt fore- 
head, is an enlargement caused by the presence of a 
huge mass of waxy substance (spermaceti) in this 
region. The mouth is on the under side of the head, 
and is somewhat behind the end of the snout. The 
teeth are large and conical, and confined to the long, 
narrow lower jaw. They number about twenty-five 
on each side, and are of a very good quality of ivory. 
In common with several of the other toothed whales 
it lives mostly on squids and cuttlefishes; nevertheless, 
fishes of considerable size are often a preponderant 
part of its diet. It is likely that the cephalopods it 



Beyond the Horizon 265 

eats give rise to the peculiar product called "amber- 
gris," the concretion of its intestine which usually 
contains the beaks of those creatures. This substance 
was formerly used in medicines but is now a con- 
stituent of the finer perfumes. It has no fragrance 
of its own, but it has the property of enhancing 
the scents with which it is combined. It is generally 
found floating on the surface of the sea or cast up 
on the shore, and, as it is one of the costliest articles 
of commerce, it can bring its chance discoverer a hand- 
some reward. The sperm whale is a native of tropical 
and subtropical seas; but, in their breeding places in 
southern latitudes, the old bulls in their fights for pos- 
session of the cows drive from their haunts the young 
males; and these, in wandering over the ocean after 
defeat, may in a sense be said to have a cosmopolitan 
range. 

As might be inferred, the possession of a set of 
powerful teeth is not attended without a certain degree 
of ferocity. Such, at any rate, is the case with the great 
killer whale, or grampus (Orca gladiator), the fiercest 
of the family. This beast is a dolphin and is the largest 
of those animals. It measures some thirty feet long. 
The conspicuous light-colored bands with which its 
body is marked serve to emphasize its somewhat for- 
bidding appearance. Seals and porpoises are not un- 
common among its captures; and it will boldly attack 
whales even larger than itself. One naturalist has 
recorded that he took thirteen porpoises and fourteen 
seals from the stomach of a single individual. The 
grampus roams the northern seas. It sometimes hunts 
in packs; and whales of goodly size have been known 



266 Dwellers of the Sea and Shore 

to throw themselves ashore in their efforts to escape 
these marauding bands. 

To the dolphins, also, belongs that odd creature the 
sea unicorn, or narwhal (Monodon monoceros) . In 
this whale the teeth are undeveloped, save in the male 
who has one long twisted tusk that projects straight 
out in front fully one half the length of the body. As 
the narwhal is twelve feet long from snout to tail, it 
will be seen that this tusk, notwithstanding that it has 
a narrow central cavity, constitutes a considerable piece 
of ivory. It is, in truth, hunted only for this tusk, the 
whalers seeming to attach little value to the carcass. 
Despite the formidable aspect of the tusk, its use to the 
animal is very obscure. Certainly the narwhal does not 
— as does the swordfish — charge boats and pierce them 
with its weapon. Nor has it been observed ever to use 
it in any other manner, offensive or defensive. It is a 
peaceable and even a playful creature; and this, to- 
gether with the fact that it swims in small herds in the 
icy waters of the North, where it feeds on small fishes, 
crustaceans, and cuttlefishes, is about all that is known 
with certainty regarding its habits. 

Closely akin to the dolphins are the porpoises. The 
fact is, between the two the fundamental difference 
seems slight, and what does exist is to be found chiefly 
in the dentition of these animals. The teeth of the 
typical dolphin are conical and pointed, and in numer- 
ous ways they strikingly resemble those of reptiles; 
whereas in the porpoise the teeth are grooved and flat- 
tened, or shovel-shaped, at the crowns. Porpoises are 
without doubt the commonest of all the cetaceans. But 
the majority of species frequent the coasts, bays, and 



Beyond the Horizon 267 

sometimes even rivers, rather than the open ocean. 
Their average length is five feet. They are sociable 
animals, usually traveling in herds, and can often be 
seen sporting playfully. Indeed, the sight of these at- 
tractive creatures is familiar to nearly every person 
who has had occasion to sail the sea, for their distri- 
bution is almost world w T ide. The bottle-nosed por- 
poise (Tursiops truncatus) is the most numerous of 
those along our Eastern shores. It follows shoals of 
herrings, on which it feeds, and is frequently caught 
with them in the nets of fishermen. In the spring, when 
the herrings make their seasonal run, the occurrence of 
this porpoise in Hempstead Harbor is not uncommon. 
To me there is something majestic in the motion of this 
animal as it plunges forward, alternately rising to blow 
and disappearing gracefully under the waves. 

The so-called "spouting" or "blowing" of cetaceans 
has not been the least of their curious attributes; and 
truly the spouting of a large whale is a spectacle never 
to be forgotten. It is not, as is commonly believed, 
even by many w T halers, the discharge of water taken in 
through the mouth; it is simply the natural process of 
breathing. Bear in mind that cetaceans hold their 
breath for longer intervals than do land animals; there- 
fore, in expelling it much greater emphasis is used. In 
rising to the surface, they forcibly rid their lungs of 
the air taken in with the previous inspiration, and this 
outrushing air is charged with water vapor due to 
ordinary respiratory changes; consequently, in the 
colder regions w T here the spouting is really more evi- 
dent, the vapor condenses and forms a conspicuous 
column of spray. Now it often happens that the animal 



268 Dwellers of the Sea and Shore 

will commence blowing just before it actually reaches 
the surface, and in that event some water is carried 
upward by the blast. It is quite possible, therefore, 
that this illusory effect has confounded many observers. 
The height to which the column ascends has also been 
subject to much exaggeration; in the very largest 
whales the spout does not exceed twenty feet at the 
highest. 

Most whales as a rule are peaceably inclined and 
inoffensive; with the exception of the killer whale and 
one or two other doubtful kinds, the greatest danger 
from a close encounter with them lies in a chance blow 
from the powerful tail. A large individual can easily 
splinter a small boat into fragments with one sweep of 
its massive flukes, gravely endangering if not destroy- 
ing the occupants outright. But for positive and pre- 
potent danger to man, we must look to the sharks who 
in this respect take precedence over every other crea- 
ture, great and small, which lives in the sea. 

Although sharks are found in all oceans, they are the 
most numerous in the tropics. Since there are more 
than one hundred and fifty described species of these 
animals, it will become apparent to the reader that the 
group is not so small as is commonly supposed. They 
are gill breathers; hence they are true fishes. Some of 
the sharks bear fully developed young; others lay eggs. 
The eggs are large in comparison with those of other 
fishes, and each one is usually contained in a tough, 
horny, quadrangular case, the corners of which are pro- 
longed into tendrillike processes apparently for the 
purpose of entangling the object in seaweeds. These 
egg cases are ofttimes carried by the waves to the 



Beyond the Horizon 269 

beach, and are popularly known as "mermaid's-purses." 
Xear the head of the embryo a slit in the case allows 
the water to enter for its respiration, the water sub- 
sequently passing out through another slit at the oppo- 
site end. On issuing from its cradle the young shark 
ruptures the end near its head, and carries with it a 
yolk bag which it retains for nourishment until such 
time as it is able to seek food. Its respiration at this 
stage of its life is performed by the aid of filaments 
projecting from the gills through the gill clefts. As it 
gets older, which is to say, by the time it uses its teeth 
efficiently, these filaments and the yolk bag disappear. 
What in most fishes which are familiar to us is a 
calcified frame — that is to say, a skeleton of bone — is 
in the sharks, a tough, or cartilaginous, structure. This 
shows that they are of a quite primitive nature, that 
they had their beginning long before bones were in 
evidence. But their claim to ancient ancestry is estab- 
lished in other ways than this; their remains are pre- 
served in rocks much older than those which hold the 
fossils of bony fishes. From the abundance of teeth 
which are found in the older deposits, it is quite prob- 
able that the sharks were much more numerous in 
former times than they are to-day. They were also 
much larger : certain individuals of one genus ( Carchar- 
odon) being over ninety feet in length. There is 
one existing species of this genus (C. rondeletii) the 
members of which are thirty feet long, but it is nearly 
extinct. The abundance of sharks' teeth is so great, in 
fact, that some of the beds in which they occur are 
quarried to obtain the fossil remains for fertilizing 
purposes. 



270 Dwellers of the Sea and Shore 

The sharks that habitually live near the shore are 
in the minority. They are of small size, and are 
usually known locally as "dogfishes." Although feed- 
ing on what fish they can catch, they are scavengers by 
nature, taking almost any animal food that comes their 
way. Some of the larger sharks of the open sea occa- 
sionally come close to shore, but their stay is only tem- 
porary as they merely make these visits in their hunt 
for prey. Many are armed with strong, sharp, cutting 
teeth with which they can do considerable execution 
among the porpoises and large fishes that they hunt; 
others, which are provided with very small teeth, feed 
only on the smaller fishes, and invertebrates. Nearly 
all of these oceanic types seem to be viviparous: in 
other words, the young are born the same as are those 
of mammals: they are incubated in the body of the 
mother, not hatched from the extruded egg. 

It is among the sharks that effect the open sea that 
occurs the common white shark (Carcharias vulgaris), 
the most dreaded monster of the deep. The genus to 
which it belongs is a large one numerically and in re- 
spect to the length of some of the species. The indi- 
viduals are generally recognized by their two large 
dorsal fins and flattened snout. It is not uncommon for 
the white shark to attain to a length of twenty-five feet 
or more. A tough, hard skin covers the body which is 
grayish brown above and white below. In the warmer 
seas where it abounds, it quite often follows in the wake 
of ships attracted by the edible parts of such refuse as 
may be thrown overboard. Not always does it confine 
itself strictly to digestible material, however; so vora- 
cious is it that often it will seize indiscriminately any 



Beyond the Horizon 271 

object within its reach. In the stomach of a white 
shark, it is said, was once found a woman's workbox; 
while the papers of a slaveship, which had been jetti- 
soned, were found in that of another. This creature 
will not hesitate to attack humans, and it is capable of 
tearing off a limb or even severing the trunk. Numer- 
ous accounts have been given of instances where a man 
armed only with a knife has gone into the water and 
worsted a shark, usually a shore shark; but here is one 
beast which man has probably never braved in its own 
element; no one could successfully cope with a brute as 
huge as this and provided w r ith such a terrible apparatus 
of saw-edged teeth. Still, it may easily be captured 
alive. South Sea Islanders are said to use a curious, 
though simple, device which consists of a floating log 
with a strong rope attached to it. At the end of the 
rope is a noose; and the animals gathering about from 
curiosity, one of their number usually succeeds in en- 
gaging its head in the trap, finally exhausting itself in 
trying to get free. Sailors catch this creature by using 
a great hook baited with a piece of meat. The hook is 
fastened to a chain, since the powerful jaws and teeth 
of the animal would bite through any ordinary rope 
with ease. 

Perhaps just as common, and even as much to be 
feared, but considerably smaller is its near relative the 
blue shark (Carcharias glaucus). This shark is pro- 
portionately more slender, and is seldom over seven 
feet long. The upper part is blue; underneath, it is 
white. Although normally a dweller of warm waters, 
it often extends its range, for it has been observed as 
far north as Long Island Sound, apparently coming in 



272 Dwellers of the Sea and Shore 

pursuit of herrings. It frequently plays havoc with the 
nets of fishing trawls, its sharp teeth cutting them to 
tatters. This is the u man-eater" shark so often figured 
in stories and tales of travel. Very likely its reputation 
is well deserved. It seems to be absolutely fearless. 
When it is captured with a hook and hauled on board, 
the utmost care is necessary in order to avoid serious 
injury from its mouth or tail. The deadly movements 
of the latter are generally interrupted by a sailor's 




MAN-EATING SHARK. 



springing forward and cutting the spine above the tail 
fin with an ax. 

The Greenland shark (Lacmargus borealis) is the 
notable exception to the order. It inhabits the cold 
northern seas, and is rarely seen elsewhere. The two 
dorsal fins are small. In size it approaches that of the 
white shark, but its head and teeth are smaller. Never- 
theless, its ability to use its jaws with effect is testified 
by many reliable observers. It is a truculent enemy of 
large whales, these having been frequently found with 
pieces bitten out of their tails by this animal. Whalers 
have reported that while a crew was occupied in cutting 
away the blubber of a killed whale, a Greenland shark 



Beyond the Horizon 



273 



approached the carcass and tore off piece after piece, 
and even after being badly wounded by them it per- 
sisted in returning to the repast. 

But — enough of the ill-reputed sharks. Now a few 
words regarding one of a very different type. This is 
the basking shark (Selache maxima) , the largest of 
them all — and, by the same token, it is the largest living 
fish. It grow r s to a length of more than thirty feet. 
The width of its mouth is extraordinary, thus giving it 
an appearance of unusual ferocity. Yet, notwithstand- 




HASKIXG SHARK. 



ing its terrifying size and forbidding aspect, it is quite 
innocuous. As a matter of fact, the creature is of a 
very timid disposition, and will readily retreat if ap- 
proached too closely. 

What is the reason for this remarkable behavior? 
The answer lies in its teeth. For a shark, they are 
amazingly small, and it is very probable that they serve 
no purpose whatever. The fish and other creatures it 
lives on are diminutive in size, and are such as would 
cause a regular man-eater shark to turn up its snout, 
so to speak. As large as is the mouth of this animal, 



274 Dwellers of the Sea and Shore 

it is capable of greater expansion, and with a single 
gulp it can capture a prodigious number of these ani- 
mals. Now, naturally, with the food that it takes in, 
a considerable quantity of water is engulfed. The pro- 
vision for the retention of this food and for the escape 
of the water is as singular as that of the whales. In 
each of the very wide gill clefts which this shark has, 
the internal opening is guarded by a sort of strainer, an 
apparatus formed by the hard supports of the gills. It 
is this sieve which allows the water to pass out of the 
mouth while holding in the organisms. Thus, in a 
sense, the creature may be said to take in its food at a 
breath. 

As its name would indicate, it loves to lie in the sun. 
It lives in the North Atlantic, and there it may be seen 
in calm weather collected in companies, with broad fin 
erect, basking motionless at the surface. 



Chapter XVI 

LIVING LIGHTS THAT NEVER DIE 

The impressions of youth are most profound — like- 
wise its illusions. The gentle breeze from over the 
harbor coming through the open window to my writing 
table, the stillness of this early hour, the stars seen sus- 
pended in the outer darkness, like sparkling motes of 
metallic dust, all bring out in realistic relief the details 
of an event now remote in time, in distance, and in the 
potentiality of its circumstances, but one which has to 
do with a type of creature I presently propose to con- 
sider. I once stood near the rail of a ship sailing a 
tropical sea. It was night. There was no moon, but 
across a glittering sky hung the luminous mist of the 
Milky Way, while standing out sharply above the 
faintly limned horizon could be seen the silvery radi- 
ance of the Southern Cross. The reflection of that 
ghostly stream and of every scintillant point shone with- 
out a tremor on the unbroken surface of the watery 
expanse like spangles on a field of sable velvet. 
Steadily the ship pushed ahead, yet seemed to remain 
motionless over that vast inverted image of the celes- 
tial panorama. The dull throbbing of her engines 
deep down in the waist, and the swift swirling of the 
waters below the forecastle head, where I was stand- 

275 



276 Dwellers of the Sea and Shore 

ing, as her sharp prow cut into the blackness, were the 
only sounds that lifted themselves in the profound 
silence of the night. Peering over the side, I beheld 
the foam streak past in the gloom. It was all aglow, 
as if the boat in her progress had stirred the water 
into a seething billow of molten glass. And far 
astern followed the wake of the vessel — a livid path 
of sulphurous light. Like a meteor lost in the mighty 
reaches of the cosmos, she seemed to be traveling 
through space, marking her course with a fiery trail. 

Then came a change. A light wind arose and the 
sea ran in ripples of fire. Coruscations of emerald and 
azure and pale orange played over the radiant crests; 
and the spray caused by the buffeting bow fell into the 
sea like a shower of shining sparks. Dissolved from 
the face of the water was the reflex of every star. 
The galaxy no longer loomed as a tremendous vapory 
swing in the solitudes of the deep. Instead, as far as 
sight could penetrate, the trembling surface gleamed 
and flamed with a light of a far different kind; and the 
colorful intensity paled even the brilliant spectacle of 
those mighty suns that shimmered in the midnight sky. 

What could be the nature of that mysterious light? 
The impulse to examine the water more closely was 
irresistible. So, tying a rope to the bail of a bucket, 
I lowered it over the ship's side. But I was not pre- 
pared for such a pull as I felt when that receptacle met 
the surface, and was nearly jerked over the rail and 
into the sea. The speed at which the boat was going 
made it seem as if the bucket had caught up a load of 
melted lead. However, I did not let go (the rope was 
new and of considerable length — therefore, valuable — 



Living Lights that Never Die 277 

and buckets on that ship were scarce; besides, I did not 
fancy an explanation for the loss, which would be cer- 
tain to invite a suspicion of my sanity), but managed 
finally to bring up the bucket with its luminous burden. 
Setting it on the deck, it stood out clearly in the sur- 
rounding darkness. By the glow of its bluish light, I 
could easily see the freckles on my hand. Dipping some 
of it up in the hollow of my palm, the escaping water 
fell to the deck in sparkling drops and ran in shining 
rivulets along the seams. Yet I could detect nothing 
therein that gave it this remarkable and mysterious 
property. Looking as closely as I could, I saw little 
patches of pulsating colors, which swiftly increased in 
brightness and then as swiftly died out again some- 
what like the embers of a fire revived to topaz bril- 
liancy by the passing breeze, and that was all. I 
emptied the contents of the bucket overboard, and re- 
mained for many minutes with my attention on the 
waters below, watching and wondering. But the sea 
did not vouchsafe its answer at that time. Indeed, little 
did I think, as I stood there, stripped to the waist, 
grimy, and still sweating from my turn in the hot stifling 
air of the stokehold, that later I would be revealing 
that and other secrets of the sea to curious readers. 
It was my first voyage, and I had never seen the ocean 
before. My knowledge of it was limited to what I had 
read in stories of adventure and travel, while living in 
a mid-Western hamlet. Of its animals I knew nothing, 
save w T hat every boy knows regarding the creatures 
which are often called upon to lend color to the exploits 
of fictional heroes. No, at that time my dream was 
that I, too, would write the selfsame manner of tales 



278 Dwellers of the Sea and Shore 

that had lured me to the sea. Such are the illusions 
of the young! Here am I, not engaged in romancing 
about the ships and men that sail the surface of the sea, 
but in detailing the lives of the lower creatures that 
range its depths. 

The nightly phosphorescence of the sea — which was 
the phenomenon just described — is as familiar to the 
traveler in the tropics as are the flying fish in the day. 
Yet not everybody knows that this is caused by the 
presence of billions upon billions of little animals each 
so minute as often to be scarcely visible to the naked 
eye. There are a number of forms which may produce 
this amazing spectacle, but the largest here is much 
smaller than the head of a pin. This one is Noctiluca, 
the most numerous and most widely distributed of all 
the light-producing creatures of the sea. In general, its 
shape may be likened to that of an apple whose stem is 
drawn out into a whiplike lash. It is with the aid of its 
large lash, or flagellum, that the tiny animal drives 
itself through the water. In structure, it is transparent 
and jellylike, and the entire organism consists of but a 
single cell. Now, this animal, small as it is, lives upon 
other organisms still smaller; and under a powerful 
glass, it may be observed to take in its food, selecting 
such things as are suitable in the surrounding medium, 
showing that it has its likes and dislikes the same as 
higher creatures whose bodies are composed of millions 
of cells. Its mouth is situated at the base of the flagel- 
lum, and is a groovelike orifice extending nearly half- 
way around one side. From the mouth issues a small 
hair-like organ, a second flagellum. The little spherical 
unit, like all cells, is made up of three principal parts: 



Living Lights that Never Die 279 

the nucleus, which here is a small granular kernel near 
the center; the cytoplasm, or cell substance, and the 
cell wall. From the nucleus can be seen radiating 
through the cytoplasm a number of branched granular 
threads. This simple structure — that is, the fact that 
Noctiluca is a one-celled creature — places it in the very 
lowest group of animals, the Protozoa. 




NOCTILUCA. (GREATLY ENLARGED.) 

In common with other protozoans, Noctiluca does 
not die from old age; in fact, barring bodily injuries or 
other accidents, it does not die at all. The reason for 
this can best be understood by examining its mode of 
reproduction. When the individual reaches a certain 
stage in its life, a division of its nucleus takes place 
which is soon followed by a constriction in the cell wall 
right around the middle of the animal. This constric- 



280 Dwellers of the Sea and Shore 

tion rapidly grows deeper, finally separating the crea- 
ture into two equal parts, each part a smaller but exact 
duplicate of its single prototype. Thus where there 
was one adult mother cell, there follows in her place a 
younger pair; and these twin daughters will in their 
turn, when they get older, proceed to divide likewise. 
In this manner the cycle continues. But it may be 
pointed out that this method of reproduction by fission, 
as it is called, does not always continue indefinitely 
without a variation. During some succeeding genera- 
tion two individuals will come together and a fusion of 
their nuclei will take place, the flagella disappear, and 
the pair seem to coalesce into a single body; reversing 
the process of division, so to speak. Eventually, how- 
ever, the fused nuclei split into numerous pieces and 
pass to the surface of the sphere where they form prom- 
inences, or buds, which ultimately become detached and 
swim away as zoospores, or young Noctilucas. When 
these grow up they will divide, and their descendants 
for a greater or lesser length of time will also continue 
to reproduce in this way. 

The color of light emitted by Noctiluca varies with 
the different species; still sometimes a single species will 
be found to give forth light of different hues. The 
beauty and intensity of the flashes are marvelous, 
coming from so small a creature, and their nature has 
been the subject of much investigation. But man has 
as yet vainly endeavored to capture its secret. He has, 
indeed, been able to isolate the chemical compounds 
which are the source of light, and has even given them 
a name, but of their ultimate nature he is still very 
much in the dark. The term "phosphorescent" ap- 



Living Lights that Never Die 281 

plied to light-producing animals owes its reason to the 
fact that the illumination resembles the glow of phos- 
phorus, but, in reality, it has nothing to do with that 
element. Phosphorus, in its free and luminous state, 
is highly poisonous to all living animal substance. 

Contrary to popular opinion, the peculiar property 
of phosphorescence is by no means a rare one or con- 
fined to a narrow range of animals. The fact is, in the 
animal kingdom, in groups extending from the proto- 
zoans to the vertebrates, there are more than three 
hundred genera containing one or more species which 
are known to emit light. The majority live in the sea. 
Of these, Noctiluca is the best known, but it is not the 
most intensely luminous. That distinction goes to a 
little ostracod crustacean bearing only the Latin name 
Cypridena hilgendorfii, because it is known to few 
others than naturalists. So powerful is the light from 
this creature that one part of its luminous gland in 
nearly two billion parts of water will give a visible glow 
to that medium. If a person possessed an organ that 
gave the same proportionate volume and intensity of 
illumination, it would be sufficient to light up the area 
of a fair-sized city. 

In the light of Noctiluca, experimenters have discov- 
ered two very interesting properties. It has no heat, 
and it has no light rays that are invisible to the eye. 
The bolometer, a heat-measuring instrument so sensi- 
tive that it can register the heat from the stars, has 
revealed — as, in truth, it has revealed in the case of all 
light-producing animals — that the phosphorescence is 
utterly without warmth, that it is what is called u cold 
light." My statement about the light rays may need 



282 Dwellers of the Sea and Shore 

elucidation. It is well known that a beam of ordinary 
sunlight actually consists of several different colors 
which can be shown on a screen by first passing the 
beam through a glass prism. This color picture is 
called the spectrum and is composed of visible hues 
ranging from deep purple through the blues and the 
yellows to deep red. If, by some suitable arrange- 
ment, a photographic plate be placed at the plane of 
the screen, excluding all other light, an image of the 
color picture will be recorded. But, in addition to 
those colors which are visible, there will appear on the 
plate a record of colors which are invisible to the eye. 
These colors are at each end of the spectrum, and are 
known as the infra-red and the ultra-violet rays. No 
artificial light has yet been devised which eliminates all 
of these invisible rays. Now, as the light of Noctiluca 
does not contain them, it will be seen that its illumina- 
tion is about one hundred per cent efficient, no light- 
producing energy being lost. However, what value 
Noctiluca — and, indeed, many another sightless ani- 
mal which could be named — derives from its power 
of luminescence is not clear. It is probable that in 
this instance phosphorescence is an incidental mani- 
festation of some fundamental cause which has for 
its end not the production of light but something much 
more remote from our comprehension. 

So thickly populated with protozoans is the sea that 
hardly a drop of water collected near the surface will 
fail to produce numerous individuals. They are, of 
course, not all light givers, like Noctiluca; but what 
they lack in this respect they often make up in exquisite- 
ness of form. Many of them secrete shells, and al- 



Living Lights that Never Die 



283 



though some giants measuring more than an inch in 
diameter are to be found in the warmer waters, most 
forms are so small as to be practically invisible. A 
wonderful work is performed by these shells in building 
the crust of the earth. They are constantly settling to 




globigerina; a protozoan, the shell of this minute animal is in the 
center, and from it radiates stiff spines of lime. enclosing the 
shell is a frothy mass of living substance from which extends 
numerous fine threads. 

the floor of the ocean. The dead shells are almost the 
sole constituent of the material that forms the bottom 
in many regions of the deep sea. They also compose 
the platforms of coral reefs. The famous chalk cliffs 
of England are made up of their countless billions 
which long ago were dropped upon the floor of the 



284 Dwellers of the Sea and Shore 

ancient sea, piling so high that some in the lower layers 
were squeezed into a shapeless mass ; then by some later 
convulsion they were lifted out of the water high into 
the air. 

The numbers which float in the sea are utterly incon- 
ceivable. The only proper estimate we can make of 
them is not to count them but to weigh them. It is 
supposed that these minute creatures are as abundant 
six hundred feet below the surface as they are at the 
top; therefore, taking this as an index, it has been 
shown that within this depth alone, every square mile 
of the ocean contains upward of sixteen tons of their 
skeletons. And this is to say nothing of the countless 
other forms which have no shells. 

In some of these creatures, the foraminifers, the 
skeletal structure is composed of lime; in others it is 
formed of silica, a transparent, glasslike substance as 
hard as flint. The latter type is peculiar to the radio- 
larians, without a doubt the prettiest of all protozoans. 
The almost endless variety of forms is a constant source 
of pleasure to the collecting microscopist, for in no 
other group of minute organisms does beauty so con- 
sistently prevail. Many are globular and perforated, 
and the soft body substance of the animal can be seen 
streaming through these apertures for food. Some are 
like fairy baskets formed of the most delicate lattice- 
work; some perforated spherical forms bristle with 
long, slender, flinty spines; and some others still have 
a crystallike sphere within an outer lacelike covering of 
glass, resembling those curious balls of jade, carved by 
the Chinese, wherein one graceful creation contains 
another still more lovely. 



Living Lights that Never Die 



285 



The foregoing facts in this chapter convey some idea 
of that stupendous abundance of animal life contained 
in the sea, whose beauties and even whose very existence 
are barely known to the world at large. But my men- 
tioning the coral reefs prompts me here to add some- 
thing in regard to another type of small creature, which, 
notwithstanding the world-wide acquaintance with its 




SHELLS OF RADIOLARIANS. (GREATLY ENLARGED.) 

skeleton, seems little known as it is in life. All corals, 
by the way, are not confined to the warm waters of the 
tropics. Some colonial forms are found on our western 
coast, and certain kinds grow in the Atlantic as far 
north as Long Island Sound, where the water is often 
icy cold. Solitary species, like Fungia, flourish in the 
cold water of very great depths. 

The reef-building corals are of a different character. 
They are rarely found below a depth of about one hun- 



286 Dwellers of the Sea and Shore 

dred and seventy-five feet, and never do they live in 
water the temperature of which is less than 68° Fahr. 
In the tropics their great reefs extend for miles and 
assume countless curious shapes, sometimes spreading 
out like a fan, or branching in every direction, forming 
figures and heads and limbs. This is characteristic of 
the Tortugas Keys off the coast of Florida, but among 
the coral reefs of the Pacific they form great circles, or 
rings, called atolls. Many reefs are exposed and flour- 
ish with vegetation, and the charm, the beauty, the 
loveliness of these verdant isles can be realized only by 
those who have passed them at sea. 

It is a curious fact that although corals have been 
familiar objects since very ancient times, their animal 
nature was not known until the eighteenth century. 
The discovery was made by an amateur naturalist who 
had succeeded in keeping some specimens of red coral 
alive in a tank. His discovery, however, was rejected 
by the professional men of science, and it was not until 
nearly twenty-five years later that they were compelled 
to recognize the truth of his claims. 

The coral animal is a coelenterate, a polyp. It re- 
sembles an anemone with the difference that it has the 
faculty of taking lime, probably from the water or from 
the food it eats, and secreting it in the chambers of its 
body, where it, the lime, forms partitions or cells, as 
the case may be. Although they live in colonies, unlike 
hydroids, each coral polyp is a complete individual in 
itself, having no physical connection with its neighbors 
other than the dead skeletal remains on which thev 
make their home. The home of each individual is 
called the corallite, and a group of these corallites, such 



Living Lights that Never Die 287 

as make up a branch of coral, is called the corallum. 
Corals reproduce by eggs, by budding, and by self- 
division. It is, in fact, due to the way in which budding 
or division takes place that the characteristic shape of 
the corallum is formed in the various species. In 
branched corals, the budding is confined to certain mem- 
bers of the colony, which results in that beautiful type; 
but the formation of so-called brain corals is caused by 
the process of division. Now if we followed the devel- 
opment of a growing coral, starting with the free- 
swimming egg, we should see it attach itself to a stone 
or some hard object and commence first to build a little 
platform or base. Then a thin edge or rim would rise 
around the periphery, increasing daily in diameter and 
height. At the same time, though unseen, the growing 
creature is building within the corallite a number of 
partitions that extend from the cuplike rim toward the 
center but do not meet. If the corallite be cut across, 
the lime that forms the rim and radiating partitions 
will have a rough resemblance to a cart wheel with the 
hub removed. The vacant area in the center contains 
the polyp's stomach. When full grown the soft tissues 
are an olive brown, and with its expanded tentacles 
looks like a tiny flower. If it should be a corallite of a 
branched coral, a bud will eventually appear on its side 
and the growth of an additional cup will take place. 
These growths will proceed until the enlarging coral 
branches out by further budding or by the division of 
the individuals. Growth is fairly rapid. Branch corals 
will grow seven or more inches in a year, and the brain 
coral has been known to attain to an inch or double its 
size in that time. Yet the reefs that they compose do 



288 Dwellers of the Sea and Shore 

not progress on any such scale as this. For although 
they are called reef builders they do not in any way 
erect a permanent structure as living animals; it is their 
skeletons, compacted in solid masses, but containing 
material wrought by other agencies as well, that make 
the reef. And it is very probable that the accretions do 
not cause it to rise more than an inch in twenty years. 

One of the factors causing the solidification of a reef 
is the work of the horde of other organisms which 
inhabit it. Such animals as crabs, mollusks, and sea 
urchins reduce and perforate the coral by scraping and 
boring and so weaken it that it breaks away in frag- 
ments ; these are in turn ground to sand by the continual 
washing of the waves, thus filling the interstices of the 
reef. Many wonderful fishes and other creatures, 
garbed in brilliant tints, make their homes in these 
stony forests, and the picture they present in the clear 
blue water of the quiet lagoons, poised among the 
branches, is one of the rarest offerings of nature. 
Occasionally one of the branches will have a group of 
large polyps, each half an inch across, the whole 
resembling a spike of pretty flowers. The colors of 
the corals, too, are various and pleasing. Some have 
red, white, or green polyps on branches of red or of 
brown. Others may have their whole mass tinted pink 
or lemon or bright blue. 

Often in the same waters with the reef builders, grow 
live corals of another type so different in appearance 
and structure that few persons would be likely to take 
them for corals. These are the sea fans and the sea 
pens and the curious organ-pipe corals. They do not 
always solely secrete lime like the madrepores (i.e., 



Living Lights that Never Die 289 

brain corals, branched corals), but instead they some- 
times form their framework of a more flexible material, 
the chief constituent of which is chitin, the horny sub- 
stance that composes the wing cases and hard parts of 
beetles and many other insects. 



gorgonia; a sea fan 



On the mud flats and coral reefs of Florida, and the 
reefs that form the keys, can be seen the sea fans grow- 
ing in vast fields, strange, exotic, and colorful. Tech- 
nically they are known as Gorgonias. They are col- 
onies of polyps having a calcareous or horny skeleton 
branching profusely in one plane. The branches are 
often fine and run together, forming a network of great 
intricacy. Some of these structures are several feet in 
length and in breadth, and are in the shape of an enor- 
mous fan. Certain varieties of Gorgonias resemble 
branching shrubs; and the shapes of others are rodlike, 



290 



Dwellers of the Sea and Shore 



long, and without branches. Still others are unbranched 
spirals, several feet in height. These are sometimes 
known as sea whips. In all Gorgonias the horny axis 
is covered with a layer of living polyps so closely united 
that they form a solid sheet of animal matter. This 
contains numerous small spicules of carbonate of lime, 
giving it a barklike, or crusty, appearance. 



v ^ 




r * £ 




..v^ £%- ^W 


! J^P ? 


'!p0&£* 


.1P& ! 


3* Jm<'E^*> 


'^ #1 


1 


5F% * 8 f . 


: \ \^m -ft 


• 


$N? 


*$. 



SPICULES OF GORGONIA. (GREATLY ENLARGED.) 



The sea pens are so named because many of them 
look very much like the quill feathers that are used for 
pens. Some of the species resemble ostrich plumes. 
The polyps are arranged along the upper part of the 
lateral branches, separate from one another. The cen- 
tral axis is naked below, and this part is buried in the 
sand. Some sea pens are capable of great expansion 



Living Lights that Never Die 



291 



and contraction. A specimen measuring about five 
inches, when taken from the deep water, was observed 




pennatula; a sea pen. 



to expand five times as large when placed in a tank an 
hour later. It was of a delicate pink by day, and by 
night it shone with a brilliant phosphorescence, the light 



292 Dwellers of the Sea and Shore 

flashing from branch to branch, and polyp to polyp. 
Nearly all sea pens are marvelous light producers. 

Among the corals of the East Indian seas is to be 
found the most peculiar, perhaps, of all, the organ-pipe 
coral. Its structure is very fragile and the cells of the 
polyps are arranged after the fashion of a pipe organ, 
from which it takes its name. The red tubular com- 
partments are separated from one another, but are 
connected at intervals by horizontal platforms. The 
polyps contained in the tops of the tubes are green, and 
save for their color, they resemble miniature daisies 
when expanded. 

The corals form much of the framework of the 
globe. The great barrier reef of Australia is over a 
thousand miles long, and in nearly every part of the 
world are found the fossil remains of reefs. One 
underlies a section of the State of New York and is in 
a way as interesting as that which now reaches out from 
Florida in the direction of Yucatan. For in its history 
is entailed the thrilling story of our continent, the story 
of an era when our waters were much warmer than they 
are to-day. 



Chapter XVII 

INTO THE DEPTHS 

No ONE has yet been able to penetrate in person the 
abyssal depths of the ocean, yet we have means of 
knowing that those regions support a strange and won- 
derful life. Nearly all parts of the sea have been 
sounded; many areas have been dredged; consequently, 
our views as to the relief of the floor and the types of 
animals associated with it are gradually becoming 
clearer. Of course this does not mean that we are 
acquainted with the habits and histories of those ani- 
mals; those things probably will take many years to 
obtain, if, indeed, such a thing is possible at all; but 
from the facts already collected, it would not be hard 
to guess how some of them live. When the vast extent 
of the ocean is considered, the number of soundings 
seem comparatively few, and for that reason it has 
often been pointed out that our knowledge concerning 
the depths is very fragmentary and limited. In a sense, 
this is true. On the other hand, if the extent of the 
ocean be great, the uniformity of conditions over vast 
areas is likewise great. A law seems to prevail that the 
deeper one goes, the more identical are the species. If 
one could walk around the world on the bed of the 
ocean, he would find the same type of animals. The 

293 



294 Dwellers of the Sea and Shore 

main cause regulating this is temperature, which in all 
seas is the same after the depth of a little more than 
a mile. 

The deepest place yet discovered in the ocean is the 
Philippine Deep which has a depth of six miles. Some 
conception of this terrific depth may be obtained when 
I say that it could contain Mount Everest, the highest 
mountain in the world, and still submerge it with more 
than a mile of water over the top. The term "deep" 
is one applied by marine naturalists to those parts of 
the ocean that are shown by soundings to be 18,000 
feet or deeper. There are known to be about sixty of 
these deeps. Depths of more than 24,000 feet have 
been recorded in ten of them, two of these abysses 
being in the Atlantic and the remainder in the Pacific. 
Between the dry land and the various deeps exists a 
well-defined area known as the continental shelf, a com- 
paratively shallow region, constantly swept by tides, 
waves, and oceanic currents to a depth of 600 feet; 
and it is separated from the deeps by an abrupt 
declivity, where the depth of the water increases 
rapidly, called the continental slope. No doubt many 
portions of the continental shelf were, at no very re- 
mote period, regions of dry land; for crossing it in 
numerous places are deep ravines that are believed to 
be submerged river valleys. In some places their con- 
nection with still existing rivers can be traced. 

In the abyssal realm, wave action no longer makes 
itself felt, the oceanic currents are absent, and the water 
is still and cold — almost freezing — and utterly without 
any light from the sun. The darkness is relieved only 
by the light of phosphorescent animals. The enormous 



Into the Depths 295 

pressure of the water — over three tons to the square 
inch — must make motion of all kinds extremely slow; 
and such fishes as are found living there are adapted to 
withstand this environment by having bodies so soft 
and delicate in structure that w T hen brought to the sur- 
face they cannot be touched without injuring them. 
Plant life, except, perhaps, bacteria or other low fun- 
goid forms, is entirely absent. The composition of the 
floor is made up of the material that filters down from 
above; these deposits, of course, varying according to 
the nature of the organisms at the surface; thus, where 
those protozoans known as Globigerina prevail, the 
ooze at the bottom is composed of carbonate of lime; 
where organisms which secrete silica abound, we find 
the floor underneath consisting of radiolarian or diatom 
ooze. However, in the very deepest parts of the ocean 
the calcareous organisms are removed by solution, and 
in some places siliceous remains are partly removed. 
In certain regions of the South Pacific Ocean far re- 
moved from the continental land, naturalists have 
brought up in their trawls hundreds of sharks' teeth 
and numerous ear bones of whales, some of which 
belong to species now extinct. Chondrites, too, which 
are found only in meteorites, and, mixed with the clay, 
magnetic spherules of metallic iron and nickel, and tons 
of manganese nodules were among the hauls. This 
abundance of teeth and bones and extraterrestrial ob- 
jects in those remote depths is owing to the fact that 
few other materials reach those regions to cover them 
up, as in other deposits. From this may be gathered 
some idea of the slow rate at which the floor deposits 
accumulate; probably not more than a foot since the 



296 Dwellers of the Sea and Shore 

time that the gigantic reptiles roamed the earth. Over 
and above this, it appears from these indications that 
of all portions of the earth's crust, the centers of the 
great ocean basins have remained the most stable since 
very ancient times. 

It was once believed that as deep-sea explorations 
became more extended, the unknown depths of the sea 
w T ould reveal some survivors of an earlier geological 
period which would fill some of the gaps in the known 
pedigree of the animal kingdom. But in only a few 
instances does this expectation appear to have been 
realized. The numbers of deep-sea species which have 
been discovered are very great, yet, generally speaking, 
they are not unlike the forms that inhabit the shallow 
waters or else they have adapted themselves to their 
changed conditions of life by special modifications of 
their structure. In fact, it is not easy to point out any 
fundamental feature wherein the deep-sea animals 
differ from those of shallower waters; what differences 
do exist are of degree rather than of kind. Therefore, 
it is thought that because the animals of the deep sea 
resemble those living in the shallow water at the present 
time, rather than those of a former age, the abyssal 
creatures may have migrated to where they now are at 
some era not long passed, comparatively speaking. Nor 
has this migration ceased. There are indications that 
the exodus from our shores, though gradual, is as 
marked to-day as at any time in the past. 

Yet, notwithstanding that the animals found in the 
deep sea are as a whole not of a primitive type, certain 
ancient crustaceans seem to have been harbored there 
since times remote, or, what is more likely, they sought 



Into the Depths 297 

the refuge of those cold, unlighted haunts as the last 
resort from the too strenuous competition imposed by 
the parvenues of the thickly populated shores. One 
form is a family of lobsterlike animals (Eryonida) 
which have fossil representatives in some very old 
rocks; another is a group of crabs {Homolodromiida) , 
which seem to be the most ancient of the existing 
brachyurans. It is also quite probable that certain 
prawns (Penaida and Acanthephyrida) found there 
are of an older type than their shallow-water relatives. 
Then, there are the Crinoids, or sea lilies. Their his- 
tory, too, is written in stone. They are often called 
stone lilies on account of their close resemblance to the 
lilies of the land. They are not plants, however, but 
are related to the starfishes. The long-jointed cal- 
careous stem is supported in the ooze by rootlike 
branches, and the top is capped with what has the 
appearance of being an inverted starfish; literally, this 
is a starfish sustained by a stem. Crinoids have existed 
from early geologic times, and apparently were once 
the only class of echinoderms; traces of their evolution 
into other forms can be followed to some extent 
through successive geologic periods. Their fossil 
forms are very abundant, showing that they once 
thrived in enormous numbers. The fact of their pres- 
ent existence is a modern discovery, for, although their 
fossils had long been familiar, no one was aware that 
there were living descendants until the deep sea was 
dredged. But they are dying out, there now remaining, 
perhaps, not more than twelve of the two hundred 
genera which are known to have formerly inhabited the 
sea. One bed of Crinoids lies off the coast of Cuba ; but 



298 



Dwellers of the Sea and Shore 



a field of particularly fine, large specimens is found in 
the waters of the Pacific near Japan. The form rep- 




THE STONE LILY; A FOSSIL CRINOID WHICH LIVED IN AN ANCIENT SEA. 



resented by the genus Pentacrinus remains perma- 
nently fixed, but the Comatula form separates from the 
stem at a certain stage in its development, and swims 




THE SEA LILY; A LIVING CRINOID. 
299 



300 



Dwellers of the Sea and Shore 



about by means of its arms. Tubular processes grow- 
ing on its body at the point where it detached itself 
enable it to fasten itself to other objects for support. 
As a rule, the individual colors of the animals in- 
habiting the depths are uniform in tone. Stripes and 
patterns, such as mark the creatures of the shore, are 
conspicuously lacking; in those Cimmerian solitudes 
there is little need for colors that warn or hues that 
hide. The echinoderms range from yellow through 
orange and red to purple, while the crustaceans are 




CERATIUSJ A FISH WHICH INHABITS THE DEEP SEA. 



mostly crimson or pink. Fishes are generally black, 
and nearly all of them are phosphorescent. Many of 
the animals are blind, as if they had long ago aban- 
doned the effort to see; their organs of touch are often 
highly developed; and they probably lead an inactive 
life, burrowing in the soft ooze or clinging to sponges 
and other low fixed forms. 

Luminous fishes have, most of them, excessively 
large eyes, seemingly adapted to catch the faintest ray 
of light; and it is probable that these apparently more 
active and predatory types are guided to their prey by 



Into the Depths 301 

its own light, or seek it out by the aid of the light that 
they emit themselves. The luminous spots or lanterns 
of many fishes are developed in such a way that the 
animals can use them to light their way in the dark 
depths, and in some forms these shining organs serve 
as veritable searchlights. For instance, in one {ALtho- 
prora) the end of the snout is covered with a phos- 
phorescent appendage that directs the light like the 
headlight of a locomotive; another has a pair of great 
flat eyes covering the whole top of the head, and the 
eyes themselves are luminous. Of these predatory crea- 
tures, many have enormous mouths and monstrous- 
looking teeth, giving them not only a frightful, but a 
fantastic appearance. And, indeed, some have been 
known actually to swallow 7 creatures larger than them- 
selves. This seemingly impossible feat is owing to the 
great distention that their soft tissues can effect. 
i\lso, their vertebrae lack specialization, and as a result 
their bodies are elongate, showing more or less degen- 
eration in those characters usually associated with sur- 
face environments. 

Although, as I have stated above, the color of deep- 
sea crustaceans is usually crimson or pink, there is much 
variation in the range of these shades. In truth, they 
are very curious in this respect. The blanched appear- 
ance that we might expect of creatures living in per- 
petual darkness, such as is known to distinguish those 
inhabiting caves, is relatively rare. More frequently, 
their colors, though uniform, are vivid, and, in some 
cases, even approaching brilliant orange. In some 
way not understood, the red color is associated 
with the darkness. This has been shown by experiment. 



302 Dwellers of the Sea and Shore 

Green crabs, when kept in partial darkness, turned 
brown; these, when kept in total darkness, turned red. 
On this account it has been suggested that the colors of 
crustaceans may be taken as an index to the depths in 
which they naturally belong. Thus, those of a pale hue 
find life more enduring when farthest removed from 
the sunlight; while the pink, red, crimson, and, finally, 
purple, blue, green, and heterogeneous forms are nor- 
mal for each succeeding higher level. But this sup- 
position cannot now be accepted without considerable 
modification. And to speak of a bathymetrical (depth- 
level) succession of colors in crustaceans would not be 
quite true. 

Deep-sea crustaceans which rest or move about on 
the soft ooze of the bottom indicate by some very ob- 
vious peculiarities of structure their manner of over- 
coming the difficulties of that mode of life. The crabs 
are mostly long-legged or spiderlike; and in a number 
of instances the legs are fringed with long stiff hairs, 
and others have spines on the body and legs, all of 
which may prevent them from sinking in the yielding 
ooze. The extremely long, slender legs of certain 
prawns are undoubtedly used as stilts by their pos- 
sessors when making their way over the floor. 

Since the temperature is constant and uniform 
throughout the world at certain depths, this renders it 
possible for many crustaceans to live in the tropical 
deep waters, which are identical with, or nearly related 
to, the shallow-water species of the colder seas. Hence, 
lobsters have been found in comparatively deep regions 
of the Indian Ocean which were very closely allied to 
a species known to occur along the shores of Norway. 



Into the Depths 303 

This to some extent explains why we find many sim- 
ilarities in the species of marine animals inhabiting the 
regions at the opposite poles of the earth. Certain 
families, genera, and even species have been observed 
in both the Arctic and Antarctic seas, yet they seemed 




NEMATOCARCINUS; A DEEP-SEA CRUSTACEAN. 

to be entirely absent in the intervening tropical zones. 
But when the latter depths were dredged, some of those 
forms were found; the low temperature of the deeper 
water offered them a connection between the North 
and South. 

In the deep sea is found that very singular family of 



304 Dwellers of the Sea and Shore 

hermit crabs, the Pylochelida. I have elsewhere in this 
work shown by internal evidence that the little hermit 
crab, Pagurus, of our shores, at one stage of its evolu- 
tion was the possessor of a lobsterlike hind body. 
Well, here, in this deep-sea form, is one whose hind 
body is segmented, perfectly symmetrical, and shows 
no indication of ever having acquired the habit of liv- 
ing in gasteropod shells. The truth is, these forms are 
so primitive that it is somewhat difficult to find many 
features by which to distinguish them from the true 
lobsters themselves. No fossil representatives of the 
hermit crab have yet been found; there can be scarcely 
any doubt that the Pylochelidae are closely connected 
with the primitive stock from which other hermit crabs 
evolved. After all, what seems most remarkable is, not 
that the abyssal crustaceans — and all other deep-sea 
animals, for that matter — are dissimilar to those of 
shallow water, but that they differ so slightly. Cer- 
tainly, it should seem from the physical conditions pre- 
vailing in those great depths, the freezing cold, the inky 
darkness, and the stupendous pressures, that their re- 
actions would be strikingly different from those of crea- 
tures inhabiting the shallow water; but, strangely, the 
differences of function are in very numerous instances 
accompanied merely by the most trivial differences in 
structure. 

From the fact that some of the free-swimming crus- 
taceans of the deep sea have been found at, or near, the 
surface, it has been supposed that they may do so for 
the purpose of spawning, which is not unlikely, con- 
sidering the sensitiveness of young animals to cold ; but, 
as shall later be pointed out, other urgent factors bring 



Into the Depths 305 

them toward the top. If, as it appears, those forms 
remaining permanently on the bottom originally came 
from near the shore, and the swimming forms de- 
scended from ancestors who swam the surface reaches, 
it may be that the young of the latter types still find in 
the surface ancestral conditions favorable to their de- 
velopment. Xor is the fact that they may come for this 
purpose in any way remarkable. The toad returns to 
the water to spawn; the land crab goes to the sea; and 
the eel goes back into its ancient habitat, the salt water, 
out of regard for the welfare of its young. It is note- 
worthy that in many of the deep-sea crustaceans, the 
eggs grow T to an enormous size before they hatch. 
From this, and from what we know of the development 
of the crayfish and certain land forms, it would appear 
that the young are born at quite an advanced stage, 
ready to lead the same life as that of the adults. In 
this connection occurs a curious thing. Blue and green 
colors, although not uncommon among shore or surface 
crustaceans, are almost never seen in the species inhab- 
iting the deep water. Yet the eggs of a large number 
of red deep-sea crustaceans are of a brilliant blue and 
often green. It is thought from this, therefore, that 
the blue pigment, common in the more familiar forms 
living at the top, is not actually absent in the deep-water 
representatives, but merely masked by the expansion 
of the red cells under the influence of their dark 
surroundings. 

The feeding habits of deep-sea animals in general 
have always been a matter of much speculation. They 
are of necessity carnivorous ; but in the absence of vege- 
tation, and all that it entails, it is clear that they could 



306 Dwellers of the Sea and Shore 

not continue mutually to subsist on one another in- 
definitely. One source of food supply is in the rain of 
dead organisms constantly descending to the bottom; 
and in the material thus settling upon the floor, the 
creatures burrowing in, or crawling over, the ooze no 
doubt find sufficient for their needs, and they, in turn, 
may serve as food for others. But there is not enough 
derived from the source just mentioned to benefit the 
whole of those myriads that swim the intermediate 
depths; so they must obtain it elsewhere. As a matter 
of fact, food is relatively scarce at the bottom of the 
deep sea, and for that reason only small forms can live 
there. Huge fishes and other gigantic creatures such 
as are associated with the surface are unknown in the 
depths, because there is virtually nothing there for them 
to eat. It was only recently that the great feeding 
ground, so to speak, c^ the swimming forms in the deep 
sea was discovered. It is near the surface. Strange 
as it may seem, these creatures, though delicately built 
to withstand pressure, are able easily to come to the 
top, and they do so at night. When the sun goes down, 
a great upward migration takes place; and during the 
darkness of the night, within a hundred yards of the 
surface, this hungry host can be found fighting and 
feasting amidst the plenitude that populates the top. 
With the breaking of the day, they return; for they are 
afraid to face the sun; in the battle with the abyss, they 
lost those weapons that would secure their safety in the 
light. 



Chapter XVIII 
LIFE IN THE ANCIENT SEAS 

What traveler has stood before the pyramids of 
Egypt without having been thrilled by the thought of 
their hoary age? One's first sight of these mighty 
monuments is invariably accompanied by a feeling of 
deep awe, by the tremendous consciousness of their 
having endured since a time so remote in the affairs of 
man that only the haziest history of their builders 
remains. Nor is the significance of their antiquity lost 
on those who have never seen them. Through printed 
books, their forms have become familiar to all; and few 
that read have failed to feel the majesty of their years. 
Throughout those many centuries that witnessed the 
ascent and decline and disintegration of one of the 
greatest empires the world has ever known, that saw 
the rise of rude and barbaric peoples to nations of the 
highest culture, they have stood mysterious, seemingly 
immutable, marking the passage of time. 

And yet the years that have passed since those piles 
w 7 ere erected are but a breath in the bosom of geologic 
time. Consider. If a small section of the stone from 
which they are constructed is put under a lens, it will 
be found in many cases to consist almost entirely of 
little shells. These shells are of considerable beauty, 

307 



3 o8 



Dwellers of the Sea and Shore 



and are the products of very ancient animals called 
nummulites. Nummulites were protozoans, and they 
lived in the sea; the shells they secreted were coinlike 
in shape (hence the name). Internally these have a 
spiral cavity divided by partitions into numerous cham- 
bers. They seem to have no external opening, but the 
chambers communicate with each other by small per- 
forations. Now the nummulites became extinct a long 
time ago; so long ago, in fact, that the earth has since 




NUMMULITES. 



been populated with other creatures, many of whom in 
their turn have died out too. So it will be seen that 
ages before the pyramids were built, perhaps before 
there was dry land where they now stand, these minute 
creatures were at work making the material out of 
which those structures were finally formed. 

It is by the fossils we find in the rocks, of course, that 
we know what lived in the ancient seas. We also have 
means of knowing what rocks are oldest; therefore, we 
are guided by the creatures they contain in forming an 



Life in the Ancient Seas 309 

idea of what types successively dominated the waters 
of our globe. It should be borne in mind, however, 
that all reliable evidence we have of ancient animal life 
is in the nature of skeletons or other hard parts which 
have been retained more or less intact or have left their 
imprint in the rocks. Undoubtedly, there have existed 
numerous forms whose bodies were so soft throughout 
that they left no trace whatever. And doubtless, too, 
many hard creatures lived w T hose parts have not been 
preserved or which have not yet been found. Indeed, 
when we come to study the land surfaces and the sea 
floors of the present time, it becomes quite obvious that 
there are so few favorable conditions for the preser- 
vation of the remains of either terrestrial or marine 
life that if former geological conditions were the same, 
which is not unlikely, the occurrence of fossiliferous 
remains may be looked upon as the result of fortunate 
accidents. 

In a preceding chapter it is mentioned that the trilo- 
bites are among the oldest known fossils. But it is 
quite certain that before they fairly had a good start 
the cephalopods appeared upon the scene to dispute 
their sovereignty. Among these, the nautilus and the 
ammonite seem to hold a prominent place. Our pres- 
ent living nautilus is the sole survivor of what in those 
early times was a very numerous race. More than 
2,500 species once swam the Silurian seas, a time in the 
history of our continent when the waters of the Pacific 
covered the western half of New York State. The 
oldest forms have straight shells; but in the course of 
time coiled shells became conspicuous; later, the race 
declined, and then they are found sometimes uncoiled 



310 Dwellers of the Sea and Shore 

or in baroque contorted shapes. Some were of gigantic 
size, one species probably weighing several tons, and 
lengths of five or more feet were not uncommon. Of 
the ammonites more than 5,000 species are known, but 
all disappeared from the ocean during the Cretaceous 
period; that is to say, while the chalk cliffs of England 
were still beneath the sea. The nautilus race declined 
more slowly, until to-day we find less than a half dozen 
species making their last stand in the depths of the 
tropical Pacific. Contrary to popular belief, they do 
not swim at the surface, but live near the bottom at a 
depth of about 1,000 feet — seldom are they found in 
water of less than 100 feet. To the inexpert eye the 
shells of ammonites and nautili might easily be mis- 
taken for one another, but there is a difference in the 
partitions that separate the chambers, and the shells of 
ammonites are usually more ornamented exteriorly 
with ridges and projections. 

Just about the time the stage was set for the mollusks 
to appear, however, another creature called the brachi- 
opod, had also established itself. And here, by the 
way, is something curious. The brachiopod, although 
not a mollusk, looks, superficially at least, strangely like 
one. Considering the popular conception of mollusks, 
I might go further and say that the brachiopod looks 
more like a mollusk than do many of those animals 
themselves. There are a few living representatives of 
this ancient animal, and they are very much like the 
ancestral type in appearance, being little changed in 
that long stretch of time since they left their dead shells 
just off the shores of the Cambrian seas. They live 
below the low-water mark, usually in depths of 100 feet 



Life in the Ancient Seas 311 

or more, but their heart-shaped shells, generally known 
as u parchment shells, M are often cast up by the waves. 
They are like the shells of bivalve mollusks, but with 
this notable difference : the valves in a clam or mussel, 
for instance, will be found on examination to be not 
exactly alike in shape ; in the brachiopod both valves are 
similar. There is no need here to go into the internal 
differences; suffice it to say that in the brachiopod these 
are so great as to make it more nearly allied to the 
worms than to the mollusks. When it flourished in its 
pristine vigor, its numbers became enormous; and it is 
one of the commonest forms among the oldest fossil- 
bearing rocks. To-day it is nearly extinct. It would be 
interesting to know why this comparatively weak and 
inactive creature has survived throughout that stagger- 
ing lapse of time, w T hile the sturdy trilobite, w 7 hose ap- 
pearance seems to be contemporaneous, died out these 
many millions of years ago. But this, like many other 
secrets of the sea, is too profound even for speculation. 
Now, if, as w T e are led to believe, the evolution of the 
lower forms preceded in point of time that of the 
higher forms, we should expect to find evidence of this 
in the rocks. Well, that is precisely what we do find. 
It is not until we reach the rocks merging into those 
which were formed in the period just preceding the 
creation of the coal beds that we come across the first 
fish. But this fish is far from looking like any that 
exists to-day. In general shape it resembles that of a 
tadpole rather than that of any modern fish. Its 
comparatively great head is depressed, projects out 
on the sides, and is attached to a slender body the 
length of which is not more than twice that of the 



312 Dwellers of the Sea and Shore 

head. Its complete outer covering is granular, resem- 
bling the rough, rasping hide of the shark. It was, 
in fact, taken for a form of that animal when first 
found. The deception was made the more easy on 
account of its sharklike tail. But when this creature 
was living, the time of the shark was not yet. In 
tracing this animal through the next succeeding series 
of rocks, we find it becomes more fishlike and the 
rough skin has for the most part given way to tough, 
horny, and in some cases bony, plates; in short, our 
creature becomes a mailed fish. Then we find that it 
becomes very numerous, many families can be recog- 
nized, and in some of them the armor has become quite 
highly specialized. Large overlapping plates invest 
the head and trunk, and the flexible hind body and tail 
are covered with hard scales. One dorsal fin was the 
rule among these armor-bearing fishes, but appended 
to the sides in the place of the pectoral fins of present- 
day forms was a pair of ponderous flippers, not unlike 
those of a sea turtle. Yet all this accouterment did not 
prevent their extinction, if indeed they may be said to 
have been exterminated by the attacks of enemies, for 
they disappeared entirely when the sharks began to 
dominate the waters of the sea. 

The coal age unquestionably saw a remarkable in- 
crease in the numbers and in the variations of the forms 
of animals. This is as true of those that lived on the 
land as well as those that inhabited the sea. Many old 
types were dying out, but they were succeeded by others 
better fitted to cope with the changing conditions of the 
globe. In point of numbers of individuals, however, 
the crinoids, corals, brachiopods, and shell-secreting 



Life in the Ancient Seas 



1^1 



protozoans far outranked all other forms; and in the 
various localities in which they thrived, each of these 
groups built up huge masses of limestone. Here, for 
the first time in the history of our earth's crust, we find 
the shell-secreting protozoans {Foraminifera) taking 
a conspicuous place among marine animals. Dense sub- 
marine groves of crinoids flourished then as probably 
they never did before, and their remains to-day are 
consolidated into deep beds of rock. Sponges grew in 
the greatest profusion. The brachiopods reached a 




PTERICHTHYS; AN ANCIENT FISH. 



great size and their shells became exceedinglv thick. 
Hardly less in importance were the mollusks, the uni- 
valve and bivalve types in particular growing increas- 
ingly abundant. Crustaceans of the higher tvpes now 
began to assume some prominence, but thev were for 
the greater part represented by the shrimps and 
prawns. Throughout this period until almost to the 
very close the sharks were in undisputed possession of 
their realm. 

And then it was that those monstrous reptilian crea- 
tures from the land invaded the sea. Like the whales, 
their structure was modified to suit their aquatic life. 



314 Dwellers of the Sea and Shore 

But what forbidding shapes they had! In one remark- 
able genus, the ichthyosaurians, the body was shaped 
like that of a fish, the four limbs were developed into 
paddles, and the tail was long and lizardlike but termi- 
nated by a fleshy fin, as in the dolphin, save that it was 
vertical. The large head was drawn out into a long 
pointed snout, resembling that of the crocodile, and the 
jaws were equipped with a series of powerful, conical 
teeth set close together. The long and slender jaws 
were strengthened to resist any sudden shock by being 
composed of numerous thin, bony plates. These plates 
also made the jaws light and flexible as well as giving 
them great strength. A feature no less striking was the 
pair of great eyes contained in the head. In some 
species these organs were more than a foot in diameter; 
and they were further remarkable from the fact that 
they seem to have been fitted to accommodate them- 
selves for vision in air or water as well as for changing 
their focal distance while the creature was in the pursuit 
of its prey. The apparatus, which could thus adjust the 
sight to the needs of the moment, was in principle not 
unlike that of a diaphragm in front of a camera lens. 
It consisted of a circle of about twenty overlapping 
plates surrounding the pupil, and as it was probably 
capable of closing completely, it must have been of 
service also in protecting the eyeball during diving. 
With eyes like these, the ichthyosaurus obviously was 
at a considerable advantage not only in discovering its 
prey at great or little distances, but in the obscurity of 
night and the depths of the sea. The masses of broken 
bones and scales of contemporary fishes that have been 
found under the ribs of these creatures make it plain 



Life in the Ancient Seas 315 

that they lived almost entirely on those animals. That 
they were very dangerous enemies of the other larger 
forms which inhabited the seas with them is evident 
from their structure; the powerful tail especially must 
have made them active in their movements, and this 
together with their predacious habits would tend to 
make them unusually formidable. The largest known 
ichthyosaurian had a head measuring about six and one 
half feet long; when found, the greater part of the 
body of this animal was missing, but it is probable that 
the head represents a total length of more than thirty- 
three feet. 

In the same family as the foregoing creatures, and 
living about the same time, was another genus of sea- 
dwelling reptiles which left a considerable number of 
well-preserved remains in the various deposits through- 
out the world. These were the plesiosaurians. None 
of them seem to have attained to the length of the 
ichthyosaurians; but it is certain that they were quite 
as voracious, if not so formidable. They lived on 
fishes, cuttlefishes, and other animal prey. The fossil- 
ized stomach contents of some of the later types show 
that they swallowed stones for digestive purposes, just 
as do the crocodiles of the present day. These strange 
creatures are considered by some naturalists to be the 
most singular in structure and in character the most 
anomalous of any that have been discovered amidst the 
ruins of former ages. Attached to a slender neck of 
enormous length was a small head, the jaws of which 
were filled with sharp gaviallike teeth. The snout was 
short, but the mouth was capable of gaping very wide. 
Its tail was somewhat short and apparently not used to 



316 Dzvellers of the Sea and Shore 

propel the animal; swimming was accomplished by the 
aid of its four large paddles which grew out from the 
trunk, and were covered with integument, forming 
simple undivided flippers, as in the turtle. Although 
nothing is known of its general habits, speculation has 
not been wanting; and it has been presumed that it 
swam on or near the surface, occasionally snapping up 
any prey which happened to come within the compass 
of its long snakelike neck; or that it may have lurked 
in the shallow water along the shore, concealed among 
the seaweeds, raising its nostrils to the surface from 
time to time for breath. Both the ichthyosaurus and 
the plesiosaurus and all their brethren that took to the 
sea had perished from the earth before the British 
Isles were raised from their oceanic crib. 

From the time of the first trilobites, the Cambrian 
age, to the era that was marked by the formation of 
those isles, that is, the age of chalk, the lapse is so over- 
whelmingly vast that there is absolutely no comparative 
measure by which it can properly be appreciated. The 
mind fails utterly in any attempt to conceive in their 
relative light the stupendous number of years that it 
must have taken to bring about what appear to be some 
of the most transient conditions in the history of the 
earth. Some day man may be able to determine quite 
accurately, in round numbers at least, the age of organic 
life on this globe; but, when all is said, the figures will 
be meaningless to the imagination. In truth, there is 
not anything within the province of language that can 
adequately convey a conception of that awful span 
which bridges the dawn of life with the chalk period. 

And how tremendously removed from the present 



Life in the Ancient Seas 317 

must be even that period! We think the pyramids 
are old. But observe; the stones with which they are 
built are obviously ages and ages older. They are com- 
posed of shells that had fallen to the bottom of an 
ancient sea; the compacted masses hardened and were 
lifted above the surface forming part of a great con- 
tinent. Yet as old as must have been the nummulites 
which formed that stone, there is strong evidence that 
when the saurians swam the seas, this species of proto- 
zoan was not yet in existence. 



Chapter XIX 
OUR SALT-WATER WORLD 

Every schoolboy knows, as Macaulay would say, 
that the ocean is one continuous sheet of water covering 
more than three fifths of the whole surface of the earth. 
And although no part of it is separated from the rest, 
the intervening land areas mark it off in five great 
divisions known as the Atlantic, Pacific, Indian, Arctic, 
and Antarctic oceans. But of the general characters 
and conditions of the sea, none of us is too highly 
aware. So our final inquiry will be directed not so much 
toward the geographical aspects of that great realm 
whose inhabitants have occupied the major portion of 
this work, but rather toward some of the physical and 
closely related aspects of the element in w T hich they live. 

Oceanography, or the science of the sea, is a com- 
paratively recent development. When scientific inves- 
tigation of the sea began we w r ere obliged to get most 
of our information from conditions prevailing near the 
shore or from mariners w 7 hose reports of conditions far 
from land were generally colored w T ith marvelous or 
frightful accounts. But w T ith the later rapid increase 
in the study of the exact sciences came the development 
and invention of accurate instruments; and w T ith the aid 
of these, observations are now easy and common. Even 

318 



Our Salt-Water World 319 

the ship's logs of to-day have special headings under 
which are listed the various phenomena as they occur 
on the surface. But undoubtedly the greatest advances 
in oceanography were occasioned by the researches of 
those expeditions made in vessels especially equipped 
for the purposes of exploration and investigation. Ob- 
viously, these are costly affairs and are not often under- 
taken; but limited as have been these enterprises, their 
achievements have been remarkable. Various govern- 
ments and private individuals have by means of these 
expeditions done much to further our knowledge of the 
open sea; however, the most noteworthy expedition 
may be said to be that of the Challenger f which was 
really the scientific pioneer of the seas. This vessel, 
under the English flag, made a voyage starting in 
December 7, 1872, and lasting until May 24, 1876. In 
this period of three and one half years she several times 
crossed and recrossed various seas; having covered in 
the entire length of the cruise nearly 69,000 nautical 
miles. From the time of this epoch-marking event 
dates the beginning of oceanography as a science of 
precision. 

Xot only is the area of the sea larger than that of the 
land, but its volume is also greater. If the entire ex- 
posed portion of the earth were dumped into the ocean, 
it w r ould not take up more than one fourth of the space 
occupied by the water; in short, it would be covered by 
an ocean 8,700 feet in depth. The mean elevation of 
the land above the sea level over the whole world is 
less than half a mile ; this is to say that if all the moun- 
tains and high portions of land could be made to fill 
the low parts the leveled earth would rise above the sea 



320 Dwellers of the Sea and Shore 

almost exactly 2,300 feet. The sea, on the other hand, 
has a mean depth of more than two miles. Nine tenths 
of it is more than a mile deep, and two thirds of its 
depth is more than two miles. 

The ocean basin, on the whole, is very smooth and 
stretches out in great level plains. All the greatest 
depths seem to occur in trenches, rather than in gradu- 
ally sloping valleys. Most of them are narrow, but are 
quite long, and their steeper side is supposed to be the 
result of a fracture in the crust of the earth. This is 
indicated by the fact that deeps are more often asso- 
ciated with regions of frequent submarine earthquakes. 
But the great deeps, those of excessive depths, are not 
nearly so extensive as is commonly imagined; the total 
area where the depth is more than three miles is prob- 
ably not more than one one hundred and forty-fifth of 
that of the sea floor. Life has been found in all of 
them, but at those depths any object is under a pressure 
of five tons to the square inch. 

It is in the Atlantic Ocean that the newer and trust- 
worthy methods of sounding have chiefly been em- 
ployed, and the contours of its floor may now be con- 
sidered as fairly well known. The greatest depth is in 
the Virgin Islands Deep, which was measured by the 
Challenger ; and it lacks 510 feet of being four and a 
half miles deep. But over the greater part of the 
Atlantic basin, the depth ranges between two and one- 
half and three and one-half miles. Along the middle, 
in a north-and-south direction, runs a great irregular 
ridge on which the depth is less than two miles, and a 
plateau of about the same depth extends almost con- 
tinuously from Newfoundland to the British Isles. It 



Our Salt-fVater World 321 

was the discovery of this plateau that facilitated the 
laying of the telegraph cables, and it is known in the 
charts as Telegraph Plateau. As this elevated plain 
approaches the British Isles, the water becomes com- 
paratively shallow; nowhere in that vicinity is the depth 
more than 400 feet. 

From the numerous islands that dot the Pacific 
Ocean, one would be inclined to believe the waters in 
their region to be somewhat shallow; but this is far 
from what is actually the case. The fact is that the 
islands rise abruptly from very great depths, and some 
of them are close to the deepest soundings that have 
yet been made. In another chapter I have mentioned 
the Philippine Deep as the deepest part of the ocean, 
but there is another deep spot almost in the same region 
which was famed for years as the greatest depression 
in the earth's crust; this is the Tuscarora Deep, off the 
coast of Japan, with a depth of slightly more than five 
and one-fifth miles. 

So far as soundings have been able to determine, the 
Indian Ocean contains no such deeps as have either the 
Atlantic or Pacific, but there are vast expanses of its 
floor forming an almost level plain at a depth of three 
or more miles. The deepest known region is the Sunda 
Trench, south of Java, where a sounding of nearly four 
and one-third miles was made. 

Of the Arctic and Antarctic oceans, the latter is con- 
ceded to be the deeper, although comparatively little 
is known about either of them. North of Siberia, the 
bed of the Arctic has a remarkably gentle slope, the 
water in that region being less than 100 feet in depth 
at a distance of one hundred and fifty miles from the 



322 Dwellers of the Sea and Shore 

shore. From this it is generally concluded to be by 
far the shallowest of all oceans. 

The deep transparent blue of the ocean has been 
celebrated in the literature of every age. In just what 
way the sea assumes its remarkable color does not seem 
to be well understood. That the depth of the water is 
in some manner associated with this phenomenon 
would appear from the fact that the purest blues are 
mostly far from land, whereas, it is well known, the 
shallows of the tropics are always green. On the other 
hand, it may be pointed out that the Rhone, at its 
emergence from Lake Geneva, and indeed the lake it- 
self, exhibits an intensity of blue which surpasses that 
of any sea. Then, there is also no doubt but that a 
distinct relationship exists between the color of the 
water and its purity, or transparency. Water that con- 
tains fewer small floating organisms is more blue than 
is otherwise the case. An increase in the turbidity is 
generally accompanied by an increasing cast of green. 
The transparency of sea water has often been measured 
in different parts of the globe, and it was found that 
great differences exist between various regions. In the 
Sargasso Sea a white disk six feet in diameter could be 
observed 216 feet below the surface; the same disk in 
the equatorial currents and the cold currents of the 
north was visible only in about half that depth. The 
purest oceanic blues are found in the warm regions of 
the Pacific and the Indian oceans and in the Sargasso 
Sea of the Atlantic. The optical property of sea water 
is of considerable biological importance, as it affects 
the penetration of sunlight and its consequent influence 
on the growth of vegetation. Every plant, of course, 



Our Salt-Water World 323 

needs light to reduce the carbonic acid required for its 
existence. Some require more, and others may want 
less; without it, however, no vegetation can live. The 
actual depth to which light penetrates obviously would 
vary in different localities, but generally speaking it may 
be said that at depths of 600 feet no light can be re- 
ceived from the sun, and even at depths considerably 
less the amount that filters through is so feeble as to 
have little or no influence on life. 

Every year approximately 475,000,000 tons of salts 
and other chemicals dissolved from the land are carried 
into the ocean by the rivers of North America alone. 
There exists at present in solution in the sea, 4,800,000 
cubic miles of salts; this quantity is more than enough 
to cover the surface of the United States one and one- 
half miles deep. Of the eighty odd know 7 n elements, 
thirty-two have been proved to exist in sea w r ater; and 
it is quite probable that as the analytical methods of 
chemistry become more refined, the presence of nearly 
all the rest will be revealed. Seaweeds and corals 
contain many of the metals, but gold and silver have 
actually been found in solution. It has been estimated 
that nearly one fifth of a grain of silver is contained 
in a ton of sea water; there is, then, dissolved in the 
sea nearly fifty thousand times as much of this precious 
metal as has been mined throughout the world since 
the discovery of America. But this is insignificant 
as compared with the quantity of gold it is presumed 
to contain. Gold is estimated to be five times as plen- 
tiful as silver in the sea. Needless to say, man has 
constantly and unsuccessfully attempted to extract the 
gold from the water. 



324 Dwellers of the Sea and Shore 

Of all the elements, sodium chloride, or common salt, 
exists in the largest amount; this being present in the 
proportion of 27.213 per 1,000 parts of water. Other 
salts exist also, though in minor quantities ; still they are 
sufficiently voluminous to impart a distinctly bitter 
taste; and they, together with the sodium chloride, 
make the water unsuitable for drinking or domestic 
purposes. 

The specific gravity of sea water is correlated with 
its salinity, or saltiness. This is merely to say that salt 
water is more buoyant than is fresh water; objects will 
not sink so readily in the sea as they will in fresh 
water. But the comparatively greater buoyancy of the 
sea is not so marked as is generally believed. It is so 
slight, in fact, as to be ordinarily imperceptible; assur- 
edly, the difference is not great enough to be detected 
by the bather, as has been frequently maintained. The 
specific gravity of pure fresh water at a temperature of 
39.2 ° Fahr. is 1, the standard unit to which the spe- 
cific gravities of all liquids and solids are referred. 
The specific gravity of the sea, out of reach of such 
exceptional influences as those of the melting snow, 
rain, or river water, is 1.02655 at a temperature of 
62 Fahr. Slight variations in the saltness of the 
ocean occur in different localities, and these necessarily 
produce corresponding changes in its specific gravity. 
On the north and south limits of the torrid zone the 
mean specific gravity appears to be less than that of the 
equatorial calm belt; and it shows a tendency to dimin- 
ish as the latitude increases. 

Where the sea is not affected by currents from 
warmer or colder regions, its temperature corresponds 



Our Sal t-Jf ater World 325 

with that of the normal temperature of the latitude. 
However, this is true only of the surface water. It has 
been shown that the temperature diminishes very rap- 
idly with the depth, in tropical and temperate latitudes 
particularly, till at great depths the ice-cold tempera- 
ture of 25 ° Fahr. everywhere prevails. At the equator, 
where the surface temperature is about 8cr, the de- 
crease with the depth is so rapid that at 360 feet from 
the top the temperature is less than 6T; at 190 feet 
it falls to 50'" ; at 4,200 feet it again falls to 40 ; and 
at a little more than one and three-fourth miles it is 
26 z . Below this depth it falls at a much slower rate, 
till in some regions it approaches very close to freezing 
temperature, which, for sea water, is about 28.6 s . In 
the equatorial belt the solar heat affects the water of 
the upper four hundred feet; but it is a remarkable 
fact that immediately beneath this sun-heated stratum 
the water in the North Atlantic as far as the fortieth 
latitude is warmer than that at the same depth at the 
equator. 

In a peculiar sense the ocean has its rivers and 
lakes as well as the land, its mighty currents and 
areas of distinct specialization. The rivers cross 
and recross, they diverge and come together, and in 
many cases they do so without mingling their w r aters 
to any great extent. The lakes, or little s^as, are 
no less distinctive in their characteristics. They are 
not distinguished by the character of their currents 
or margins, however, but by the floating vegetation 
they contain. 

The nearest of these tracts to our shores is the Sar- 
gasso Sea in the Atlantic, between Bermuda and the 



326 Dwellers of the Sea and Shore 

Virgin Isles. It consists largely of great drifting fields 
of the fucoid seaweed Sargassum, commonly called the 
gulfweed. It is the same plant which composes similar 
"seas" in the Pacific and Indian oceans. Although its 
quantities are enormous, and although it has never been 
found otherwise than while floating, there is reason to 
think that this seaweed grows originally on the bottom 
of comparatively shallow parts of the sea. Its presence 
in the north Atlantic is regarded by voyagers as a cer- 
tain indication of the Gulf Stream, by which it is car- 
ried northward and eastward. 

Of all the great oceanic rivers, the Gulf Stream is the 
most important and the most widely known. Starting 
in the Gulf of Mexico, from which it derives its name, 
it flows between the coast of Florida on one side, and 
Cuba and the Bahamas on the other, and passes north- 
east along the American coast until it reaches the 
island and Banks of Newfoundland, when it veers 
across the Atlantic and divides into two divergent parts, 
one of which swings east toward the Azores and the 
coast of Morocco, while the other washes the shores 
of the British Isles and Norway, and continues in its 
onward course past the southern coasts of Iceland and 
Spitzbergen, finally losing itself in the Barents Sea 
and the Arctic Ocean. As it leaves the Florida Straits, 
which is its narrowest portion, it is fifty miles wide; 
here with a velocity of three and one-third miles an 
hour it sweeps along majestically like an immense tor- 
rent. As it proceeds its speed diminishes and its cur- 
rent gradually grows wider. By the time it has passed 
the Newfoundland Banks its width has expanded for 
hundreds of miles. 



Our Salt-Water World 327 

The waters of the Gulf Stream are of a deep sap- 
phire blue, and they show a sharp contrast to the light 
green of the seas through which they pass in their early 
course. As this mighty river leaves the Gulf of Mexico, 
it has a temperature of 84 in summer, which is four 
degrees higher than obtains in the ocean at the equator. 
Even in mid-Atlantic, off Nova Scotia, its temperature 
at no season falls more than 15 ; while the northwest- 
ern coasts of Europe are laved by its warm waters, 
waters which were heated more than 1,400 miles away 
under a tropical sun. As a result their winter tempera- 
tures are raised about 30 above the normal tempera- 
tures of the latitudes. To its beneficent and genial 
warmth, England owes its humid climate, and Ireland 
its perennial green. Scotland, graced with verdure 
throughout eleven months of the year, is in the same 
latitude as is the bleak and frozen coast of Labrador. 
And even Lisbon, though in the mild region of the 
Mediterranean, is not unaffected by the flow of its 
southward course. Here, too, a parallel may be drawn. 
In the same latitude Washington is subject to blizzards, 
and the Potomac sometimes freezes in a single night; 
Lisbon scarcely knows a frost. 

For the cause or causes of the Gulf Stream, we must 
turn to the trade winds. These winds prevail along 
the equatorial belt, and blow steadily all year from east 
to west. Their strength and impetuosity may vary, but 
they are always in evidence. They encircle the globe, 
and are the primary cause of every other great oceanic 
current. Westward in the Atlantic Ocean, their con- 
tinuous action sets up a flow of water just north of the 
equator; and this water, encouraged by these winds, 



328 Dwellers of the Sea and Shore 

starts slowly toward the northeast coast of South 
America where it is deflected into the Caribbean Sea, 
flowing thence between Yucatan and Cuba into the Gulf 
of Mexico. The Gulf acts as a great reservoir, and 
the waters thus wafted into it raise its surface several 
feet above the level of the Atlantic. As there are but 
two straits connecting the Gulf of Mexico with the out- 
side ocean — the Yucatan channel through which the 
trades are continuously forcing more water, and the 
passage between Florida and Cuba — the Gulf is obliged 
perforce to discharge its pent-up waters through the 
opening that offers the least resistance. Therefore, it 
pours out its mighty volume through the narrow pass- 
age in the east, where they round the Florida keys and 
turn to the north. Until the Gulf Stream passes Cape 
Hatteras, North Carolina, it clings to our coast rather 
closely; beyond that point it stretches out into the cold 
waters of the north. As a result the seaboard below 
the cape is not exposed to any cold currents, and the 
temperature of the adjacent region is modified from the 
heat of the Gulf Stream. The shores to the north of 
the cape, on the contrary, are exposed to a great cur- 
rent from the Polar Seas, which runs inside and counter 
to the Gulf Stream, and comes freighted with ice from 
the northern latitudes. In midwinter, off the inclement 
coasts of our continent, between Cape Hatteras and 
Newfoundland, ships beaten back from their harbors 
by fierce northwesters, buffeted and loaded down with 
ice and in danger of foundering, turn their prows to the 
east, and find relief and comfort on the bosom of the 
Gulf Stream. 

Although the Pacific Ocean has its great equatorial 



Our Salt-Water World 329 

or trade-wind current, it has no great basin like the 
Gulf of Mexico to store the waters of another Gulf 
Stream; no other ocean but the Atlantic contains a 
current of such energy and volume. And no other cur- 
rent affects so large a part of the surface of the earth. 
At first sight it seems incredible that a current of water 
should force itself through the ocean with distinct 
boundaries and with a different color, temperature, and 
even inhabitants (for the creatures which live in its 
tropical warmth seldom stray into the colder seas), 
like a mighty river between its banks, flowing for thou- 
sands of miles against counter-currents which some- 
times actually cross its course, passing under by their 
greater density, until it loses its momentum on the 
shores of far-off continents or spreads out in the dis- 
tant north to temper the frigid seas. But all this, as 
closer observation will soon convince us, is in accord- 
ance with the physical laws of fluids. It is well known 
that great inland streams, such as, for instance, the 
clear waters of the Mississippi and the turbid currents 
of the Missouri, do not unite at once at their conflu- 
ence, but continue side by side for many miles before 
they mingle. And all great rivers running into the 
ocean are rivers still, far out at sea. The Rio de la 
Plata, which drains the southern part of South America, 
continues to flow after it leaves the land, and can be 
perceived in its course two hundred miles from the 
shore. The Amazon runs far into the Atlantic, though 
it is there gradually bent to the north by the trade- 
wind currents, and helps, with the waters of the Ori- 
noco, to swell the Gulf of Mexico. From this it will 
be seen that the Mississippi, the Rio Grande, the Ori- 



330 Dwellers of the Sea and Shore 

noco, and the Amazon all contribute to the waters of 
the Gulf Stream. 

Such, in brief, is the nature and capacity of the Gulf 
Stream — preeminently the most potent factor for the 
progress of civilized man. Without its influence, the 
greater part of cultured Europe would be a cold and 
cheerless waste, uninhabited save by such rude races as 
the Eskimos and Lapps. Over a large part of our own 
salubrious land would descend long and dreary winters, 
and desolation would prevail throughout what are at 
present the fairest and loveliest portions of the earth. 



INDEX 



Acanthephyridoe, 297 
zEthoprora, 301 
Aglaophemia strut/iioides, 177 
Ammonite, 309 
Amphineura, 46 
Antennularia antennina, 177 
Aphrodite, 27, 216 
Archilenthus, 199 
Arctic whale, 260 
Asterias, 50 
Asteroidea, 50 
Aurelia flavidula, 78 

B 

Balcena biscayensis, 262 
B. japonica, 262 
B. mysicetus, 261 
Baloenidoe, 260 
Baloenopteridoe, 260 
Barnacles, 9 
Basking shark, 273 
Biscayan whale, 262 
Black whale, 262 
Bladder wrack, 131 
Blood worm, 214 
Blue crab, eggs of, 108 
Blue shark, 270 
Blue whale, 259, 262, 263 
Boring sponge, 166 
Bottle-nosed porpoise, 267 
Brachiopod, 310 
Brittle star, 51 
Brown anemone, 113 



Cachalot, 264 
Callithamnion, 



134 



Campanularians, 172, 174 

Cancer irroratus, 72 

Caprella, 9 

Carcharias glaucus, 271 

C. rondeletii, 269 

C. vulgaris, 270 

Carrion beetles, 146 

Cephalopods, 46, 199 

Chalinopsilla arbuscula, 166 

C. oculata, 165 

Ceramium, 134 

Cetacea, 258, 259 

Cicindela dorsalis, 149 

Cladophora, 120 

Clava leptostyla, 97 

Cliona sulphurea, 166 

Clytea poterium, 174 

Coelenterata, 83 

Comatula, 298 

Comb jelly, 74 

Comb worm, 212 

Comet jelly, 75 

Coral, 285 

Coral Una officinalis, 133 

Corallines, 132 

Crinoids, 52, 297 

Ctenophora, 74 

Cuttle fish, 198, 206 

Cyanea arctica, 79 

C. fulva, 76 

Cypridena hilgendorfii, 281 



Devil fish, 198, 199 
Diatom, 295 
Dolphin, 259, 264 



331 



332 



Index 



Echinoidea, 50 
Eel grass, 138 
Enchytraeids, 146 
Enteromorpha, 120, 125 
Erax rufibarbus, 148 
Eristalis, 148 
Eryonidoe, 297 



Feather star, 52 
Fiddler crab, 138, 240 
Flat fish, 18 
Flat worms, 209 
Flesh flies, 146 
Flounder, 18 
Fucus, 127 

Fundulus majalis, 196 
Fungia, 285 



Gasteropoda, 46 
Glass prawn, 193 
Globigerina, 295 
Gorgonia, 289 
Grampus, 265 
Grantia ciliata, 167 
Greenland shark, 272 
Greenland whale, 260 
Griffithsia, 133 
Gulf Stream, 326 

H 

Hermit crab, 72, 87 
Homolodromiidoe, 297 
Humped-back whale, 260, 263 
Hydractinia, 180 
Hydroids, 171 
Hydrozoa, 171 
Hypnea, 133 



Ichthyosaurus, 259, 314 
Idotea metallica, 150 



K 

Kelp, 130 

Killer whale, 265 



Lacmargus borealis, 272 
Laminaria, 121, 130 
Libinia dubia, 191 
L. emarginata, 191 
Limulus, 217, 225 
Littorinidoe, 46 
Lyngbya majuscula, 125 

M 

Man-eater shark, 272 
Mason worm, 212 
Meckelia ingens, 209 
Mermaid's hair, 125 
Metridium marginatum, 113 
Microciona prolifera, 166 
Mnemiopsis leidyi, 74 
Mollusca, 46 
Monodon monoceros, 266 
Moon snail, 32 
Mud snail, 95 
Mummichog, 196 
Mussel, 29, 35 
Mystacoceti, 259 

N 
Narwhal, 266 
Nassa, 95 
Nautilus, 201, 309 
Necrophorus, 146 
Nereis, 27, 216 
Noctiluca, 278 
Nummulites, 308 



O 

Obelia commissuralis, 
Octopus, 198, 202 
Odontoceti, 259, 264 
Orca gladiator, 265 
Orchestia, 24, 146 
Organ-pipe coral, 292 
Oscillaria, 125 
Osmerus arcticus, 264 



175 



Index 



333 



Pagurus longicarpus, 87 

PaLemonetes vulgaris, 193 

Pelecypods, 43, 46 

Penoedoe, 297 

Pentacrinus, 298 

Periwinkles, 46 

Philippine Deep, 294, 321 

Phyllophora, 133 

Physalia arethusa, 182 

Pliyseter macrocephalus, 264 

Plesiosaurus, 315 

Pleurobrachis rhododactyla, 75 

Plumularians, 172, 176 

Poly cirrus eximius, 214 

Polynoe, 88 

Polysiphonia, 133 

Porpoise, 266 

Portuguese man-of-war. 182 

Pseudopleuronectes am eric anus, 

187 
Pteropods, 261 
Ptilota, 133 
Pylochelidoe, 304 

R 

Radiolarians, 284, 295 
Rainbow jelly, 74 
Razor clam, 44 
Ribbon worm, 209 
Right whale, 260 
Robber fly, 148 
Rorqual, 259, 262, 263 



Sand crab, 72 
Sarcophagus, 146 
Sargasso Sea, 325 
Sargassum, 120, 326 
Scale worm, 88 
Scaphopoda, 46 
Sea cucumber, 52 
Sea lily, 52 
Sea pen, 290 
Sea unicorn, 266 
Selache maxima, 273 
Serpula, 212 



Sertularia argentia, 172 
S. cupressina, 172 
S. pumilla, 172 
Sharks, 268 
Shipworm, 55 
Sow bug, 150, 223 
Spartina, 138 
Sperm whale, 199, 264 
Spider crab, 71 
Spirulina, 125 
Squid, 86, 195, 198, 199 
Staphylinids, 146, 147 
Stone lily, 297 
Sunda Trench, 321 



Tabanus co stalls, 147 

Talitrus, 146 

Telegraph Plateau, 321 

Teredo, 55 

Thamnocnidia spectabilis, 17! 

Tides, 17 

Tiger beetle, 149 

Toothed whales, 264 

Trade winds, 327 

Trilobite, 223 

Tubularians, 172, 178 

Tursiops truncatus, 267 

Tuscarora Deep, 321 

U 

Uca minax, 240 
Uca pugilator, 138 
Ulva, 120, 125. 137 
Urn sponge, 167 



Virgin Islands Deep, 320 

W 

Whalebone whales, 259 
White anemone, 27 
White shark, 270 



Zostera, 138